Penis - phallus

Don't confuse the very similar nouns penis and phallus (archaically phallos, the transliteration of the Greek φαλλὁς, from which the Latin is derived).

• The penis is the male sexual and urinary-genital organ. Penis is a comparatively neutral term.

Etymological note: penis is a Latin word for 'tail', extended in Roman times to what we now call a penis. The Latin plural form of penis is penes; AWE recommends students to use the regular English formation of penises.

• The phallus is the penis in its erect state - that is, stiff, ready for sexual action. OED (2005) defines it as "[t]he penis, esp[ecially] as an organ of symbolic significance; (sometimes) spec[ifically] an erect penis", but in ordinary usage it has become almost entirely restricted to the erect organ.

Etymological note: phallus is froim the same root as follis, the Latin for 'bellows'. The same proto-Indo-European root, *bhel-, with a general sense of 'inflated', 'bag [of wind]', gives us fool and foolish. The coincidence may inspire some thought in users of AWE.
The Greek plural of φαλλὁς is φαλλοί, phalloi; the Latin plural of phallus is phalli. AWE recommends readers to use the more regular English form phalluses.

• • The little used adjective ithyphallic (obsoletely ithyphallian), prefixing 'phallic' with 'ithy-', the Greek ἰθύς, for 'straight', makes the distinction from 'penis' more clearly. Hence its other meaning "Grossly indecent, obscene". It was also applied, as a noun, to the "licentious or indecent" verse composed in honour of such deities as Priapus.