What is "tardation"

Tardation \Tar*da"tion\, n. [L. tardatio, fr. tardare, tardatum, to retard, delay, fr. tardus slow.] The act of retarding, or delaying; retardation. [Obs.]

"slowness," c.1500, from Late Latin tardationem (nominative tardatio), noun of action from past participle stem of tardare "to slow," related to tardus "slow, sluggish" (see tardy).

n. (context obsolete English) The act of slowing or delaying; retardation.