c. 1300, "characterized by intellectual depth, very learned," from Old French profont, profund (12c., Modern French profond) and directly from Latin profundus "deep, bottomless, vast," also "obscure; profound; immoderate," from pro "forth" (from PIE root *per- (1) "forward") + fundus "bottom" (see fund (n.)).
The literal and figurative senses both were in Latin, but English, having already deep, has employed this word primarily in its figurative sense; however in 15c. it was used of deep lakes or wounds. Sense of "deeply felt, intense" is from c. 1400. Related: Profoundly. A verb profound "to penetrate, reach inside, saturate, fill" is attested in English from 15c.-17c.
early 15c., refounden, refunden, "to pass on, transmit;" also "to return" (earlier "to pour back," late 14c.); from Old French refunder, refounder, refondre "restore" and directly from Latin refundere "give back, restore, return," literally "pour back, flow back," from re- "back" (see re-) + fundere "to pour" (from nasalized form of PIE root *gheu- "to pour").
Century Dictionary speculates that Old French refounder in the sense "restore" was confused with refonder, refunder, "re-establish, rebuild, restore ("refound"). In some senses also influenced by fund (n.). Specifically as "to resupply with money" from 1550s. Related: Refunded; refunding.
"to make a common interest or fund, put things into one common fund or stock for the purpose of dividing or redistribution in certain proportions," 1871, from pool (n.2). Related: Pooled; pooling.