Wordnet 3.0
NOUN (1)
1.
the 13th letter of the Hebrew alphabet;
The Collaborative International Dictionary of English v.0.48:
mem \mem\ n.
the 13th letter of the Hebrew alphabet.
[WordNet 1.5]
WordNet (r) 3.0 (2006):
mem
n 1: the 13th letter of the Hebrew alphabet