security pledged for the payment of a loan

He gave the bank some stocks and bonds as collateral for the money he borrowed.

Anatomy .

a subordinate or accessory part.

a side branch, as of a blood vessel or nerve.

collateral circulation.

a relative descended from the same stock, but in a different line.

accompanying; auxiliary

He received a scholarship and collateral aid.

additional; confirming

collateral evidence; collateral security.

secured by collateral

a collateral loan.

aside from the main subject, course, etc.; secondary

These accomplishments are merely collateral to his primary goal.

descended from the same stock, but in a different line; not lineal

A cousin is a collateral relative.

pertaining to those so descended.

situated at the side

a collateral wing of a house.

situated or running side by side; parallel

collateral ridges of mountains.

Botany . standing side by side.

adjective

chief , direct , main , primary , principal

adjective

accessory , accompanying , added , adjunctive , adjuvant , ancillary , appurtenant , attendant , auxiliary , circuitous , coincident , complementary , concomitant , concurrent , confirmatory , coordinate , corresponding , corroborative , dependent , incident , lateral , not lineal , parallel , related , roundabout , satellite , side , sub , subordinate , subservient , subsidiary , supporting , tributary , under , assistant , contributory , supportive , subject

noun

assurance , bond , endorsement , guarantee , pledge , promise , security , surety , warrant , wealth , added , ancillary , concomitant , indirect , secondary , subordinate , subsidiary