mat·ro·nym·ic 
(măt′rə-nĭmĭk) also me·tro·nym·ic (mē′trə-, mĕt′rə-)
(măt′rə-nĭmĭk) also me·tro·nym·ic (mē′trə-, mĕt′rə-)adj.
Of, relating to, or derived from the name of one's mother or maternal ancestor.
n.
A name so derived.
[Greek mātrōnumikos, dialectal variant of mētrōnumikos : mētēr, mētr-, mother; see METRO- + onuma, name; see n-men- in the Appendix of Indo-European roots.]