from
The Collaborative International Dictionary of English v.0.48
Decimate \Dec"i*mate\, v. t. [imp. & p. p. {Decimated}; p. pr. &
vb. n. {Decimating}.] [L. decimatus, p. p. of decimare to
decimate (in senses 1 & 2), fr. decimus tenth. See
{Decimal}.]
1. To take the tenth part of; to tithe. --Johnson.
[1913 Webster]
2. To select by lot and punish with death every tenth man of;
as, to decimate a regiment as a punishment for mutiny.
--Macaulay.
[1913 Webster]
3. To destroy a considerable part of; as, to decimate an army
in battle; to decimate a people by disease.
[1913 Webster]