Alternative forms 
From Middle English inborȝ (“bail”), from Old English inborh (“bail, security in cases of theft, a security required in cases where property had been stolen”), from in- + borh, borg (“a security, pledge, loan, bail; payment”), equivalent to in- + borrow. Related to Old English borgian (“to borrow; lend; be surety for”). More at borrow.
inborrow (plural inborrows)
- (obsolete) Security; bail.
- (obsolete) One who gives or offers security for another; a surety.
- inborrow and outborrow