noun:

1. In a barbershop quartet, the person who sings the melody, usually the second tenor.
2. The situation where a runner steps away from a base while waiting for the pitch to be thrown.
3. The axial distance a screw thread travels in one revolution. It is equal to the pitch times the number of starts.
4. An insulated metallic wire for electrical devices and equipment.
5. A heavy, pliable, inelastic metal element, having a bright, bluish color, but easily tarnished; both malleable and ductile, though with little tenacity. It is easily fusible, forms alloys with other metals, and is an ingredient of solder and type metal. Atomic number 82, symbol Pb (from Latin plumbum).
6. The person in charge of a project or a work shift etc.
7. A mark or a short passage in one voice part, as of a canon, serving as a cue for the entrance of others.
8. The act of leading or conducting; guidance; direction, course.
9. The announcement by one voice part of a theme to be repeated by the other parts.
10. Information obtained by a news reporter about an issue or subject that allows him or her to discover more details.
11. A thin cylinder of black lead or plumbago (graphite) used in pencils.
12. A teaser; a lead-in; the start of a newspaper column, telling who, what, when, where, why and how. (Sometimes spelled as lede for this usage to avoid ambiguity.).
13. Potential opportunity for a sale or transaction, a potential customer.
14. The act or right of playing first in a game or round; the card suit, or piece, so played.
15. Sheets or plates of lead used as a covering for roofs.
16. A lode.
17. The distance of haul, as from a cutting to an embankment.
18. A thin strip of type metal, used to separate lines of type in printing.
19. A rope, leather strap, or similar device with which to lead an animal; a leash.
20. The excess above a right angle in the angle between two consecutive cranks, as of a compound engine, on the same shaft.
21. A plummet or mass of lead attached to a line, used in sounding depth at sea or to estimate velocity in knots.
22. The course of a rope from end to end.
23. Hypothesis that has not been pursued.
24. Information obtained by a detective or police officer that allows him or her to discover further details about a crime or incident.
25. The actor who plays the main role; lead actor.
26. The advance of the current phase in an alternating circuit beyond that of the electromotive force producing it.
27. A roof covered with lead sheets or terne plates.
28. Bullets; ammunition.
29. A channel of open water in an ice field.
30. In a steam engine, the width of port opening which is uncovered by the valve, for the admission or release of steam, at the instant when the piston is at end of its stroke.
31. Precedence; advance position; also, the measure of precedence; the state of being ahead in a race; the highest score in a game in an incomplete game.
32. Charging lead.
33. The action of a tooth, such as a tooth of a wheel, in impelling another tooth or a pallet.
34. An important news story that appears on the front page of a newspaper or at the beginning of a news broadcast.
35. The angle between the line joining the brushes of a continuous-current dynamo and the diameter symmetrical between the poles.
36. Vertical space in advance of a row or between rows of text. Also known as leading.
37. The player who throws the first two rocks for a team.
38. The main role in a play or film; the lead role.

verb:

1. To produce (with to).
2. To live or experience (a particular way of life).
3. To go or to be in advance of; to precede; hence, to be foremost or chief among.
4. To be more advanced in technology or business than others.
5. To guide or conduct oneself in, through, or along (a certain course); hence, to proceed in the way of; to follow the path or course of; to pass; to spend. Also, to cause (one) to proceed or follow in (a certain course).
6. To lead off or out, to go first; to begin.
7. Misspelling of led.
8. To guide or conduct, as by accompanying, going before, showing, influencing, directing with authority, etc.; to have precedence or preeminence; to be first or chief; — used in most of the senses of the transitive verb.
9. To place leads between the lines of.
10. To guide or conduct in a certain course, or to a certain place or end, by making the way known; to show the way, especially by going with or going in advance of, to lead a pupil; to guide somebody somewhere or to bring somebody somewhere by means of instructions.
11. (heading, transitive) To guide or conduct.
12. To guide or conduct with the hand, or by means of some physical contact connection.
13. To conduct or direct with authority; to have direction or charge of; to command, especially a military or business unit.
14. (heading) To begin, to be ahead.
15. To direct; to counsel; to instruct.
16. To draw or direct by influence, whether good or bad; to prevail on; to induce; to entice; to allure.
17. To cover, fill, or affect with lead.
18. To tend or reach in a certain direction, or to a certain place.

adjective:

1. Foremost.
2. Main, principal.