I. ˈsigˌmāt transitive verb
( -ed/-ing/-s )
Etymology: sigma + -ate (v. suffix)
: to affix a sigma or s to (a root) in forming a tense or a plural
II. adjective
Etymology: sigma + -ate (adjective suffix)
1. : having the shape or form of the Greek sigma or the letter S
2. of a sponge spicule : c-shaped