1. cell from which another cell of an organism (usually of a different sort) develops; - Example: "a sperm cell develops from a sperm mother cell"
The Collaborative International Dictionary of English v.0.48:
Mother \Moth"er\, a.
Received by birth or from ancestors; native, natural; as,
mother language; also acting the part, or having the place of
a mother; producing others; originating.
It is the mother falsehood from which all idolatry is
derived. --T. Arnold.
Mother cell (Biol.), a cell which, by endogenous divisions,
gives rise to other cells (daughter cells); a parent cell.
Mother church, the original church; a church from which
other churches have sprung; as, the mother church of a
Mother country, the country of one's parents or ancestors;
the country from which the people of a colony derive their
Mother liquor (Chem.), the impure or complex residual
solution which remains after the salts readily or
regularly crystallizing have been removed.
Mother queen, the mother of a reigning sovereign; a queen
(a) A language from which another language has had its
(b) The language of one's native land; native tongue.
Mother water. See Mother liquor (above).
Mother wit, natural or native wit or intelligence.
WordNet (r) 3.0 (2006):
n 1: cell from which another cell of an organism (usually of a
different sort) develops; "a sperm cell develops from a
sperm mother cell"