put lead in one's pencil

put lead in (one's) pencil

Of a man, to increase, enhance, or restore one's sexual ability or vigor. Following this six-step program will put lead in your pencil, guaranteed. The only real way to put lead in your pencil is to eat well, exercise regularly, and have self-confidence.
See also: lead, pencil, put
Farlex Dictionary of Idioms.

put lead in one's pencil

Enhance or restore sexual vigor, as in Try one of these hot peppers; that'll put lead in your pencil. This phrase, a euphemism for causing an erection, is considered far more vulgar than the contemporary synonym put hair on one's chest, alluding to a secondary male sex characteristic. [Colloquial; c. 1900]
See also: lead, pencil, put
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • put lead in (one's) pencil
  • put lead in your pencil
  • lead in (one's) pencil
  • lead in your pencil
  • pencil
  • have lead in (one's) pencil
  • have lead in one’s pencil
  • pencil in
  • pencil me in
  • in pencil