The Collaborative International Dictionary
Mainpernable
Mainpernable \Main"per*na*ble\, a. [OF. main hand + pernable, for prenable, that may be taken, pregnable. See Mainpernor.] (Law) Capable of being admitted to give surety by mainpernors; able to be mainprised.
Wiktionary
mainpernable
a. (context legal English) Capable of being admitted to give surety by mainpernors; able to be mainprised.