I. noun
1.
a. : husband
a married woman steppin out on her old man — James Jones
— not often in formal use
b. : father
my old man was not any great shakes as a parent — Damon Runyon
— not often in formal use
c. usually capitalized O&M : boss
was not wholly satisfied with the way the Old Man was running the department — H.S.Commager
especially : commanding officer
the Old Man pointed her head for Nantucket Sound — H.A.Chippendale
— not often in formal use
2.
a. : one having the skill or status acquired through long experience : recognized authority
the great old man of Eurasian archaeology — O.J.Maenchen-Helfen
b. : a senior member or former member of an organization (as a military unit)
the old men who had fought in the regiment's first two battles — Dan Levin
c.
(1) : a tribal elder or sage
the old man … presides at ceremonials — C.D.Forde
(2) usually capitalized O&M : culture hero
marks on the birch tree … inflicted in a moment of anger by Old Man — W.D.Wallis
d.
(1) : old adam
put off … the old man, which is corrupt according to the deceitful lusts — Eph 4: 22 (Authorized Version)
(2) : god
3. Australia : a full-grown male kangaroo
4.
a. : southernwood
b. : rosemary
5. dialect England : the last sheaf of the harvest sometimes shaped into a human effigy and buried
6. : a drilling post for use with a ratchet, electric, or pneumatic drill
II. noun
: boyfriend ; especially : one with whom a woman cohabits