To tweek or pinch the erect nipple as if it were the tuning knob on an analog radio. Popularized after WWII because the act of inexperienced males trying to please women resembled WWII radio operators adjusting the equipment knobs to 'tune in Tokyo'.

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed

Tweaking or twisting the nipples of a female's breasts, particularly when done in an awkward or clumsy manner.

Used to describe sexual acts concerning female breasts. Usually used to describe feeling them, or playing with the nipples to stimulate sexual arousement.