ten/tain/tin

hold, keep

Spelled ten, tain, tin · tenere 'hold, keep'

Latin tenere means hold: contain holds things together, retain holds them back, and tenacious describes someone who keeps holding on.

Words built from it

tenacious — holding firmly to something; unwilling to give up
ten (hold) + -acious (inclined to)
tenable — able to be defended with good reasons
ten (hold) + -able (able to be)
contain — to hold or have something inside
con- (together) + tain (hold)
retain — to keep possession of something
re- (back) + tain (hold)
detain — to hold someone back or keep someone in custody
de- (back) + tain (hold)
sustain — to support or keep something going
sus- (from below; form of sub-) + tain (hold)
abstain — to choose not to do or take something
abs- (away; form of ab-) + tain (hold)

tenuous — Comes from Latin tenuis (thin), not from tenere (hold), the root taught here.
tender — Contains ten, but comes from Latin tener (soft, delicate), not tenere (hold).