"straps for holding up trousers, etc.," 1806, American English, plural of suspender "one who or that which causes to hang by support from above" (1520s), agent noun from suspend (v.).
Entries linking to suspenders
suspend v.
c. 1300, suspenden, "to bar or exclude temporarily from some function or privilege;" also "to set aside (a law, etc.)" and in a general sense of "cause to cease for a time," from Old French sospendre "remove from office; hang up" (12c.), or directly from Latin suspendere "to hang up, kill by hanging; make uncertain, render doubtful; stay, stop, interrupt, set aside temporarily," from assimilated form of sub "up from under" (see sub-) + pendere "to hang, cause to hang; weigh" (from PIE root *(s)pen- "to draw, stretch, spin").
In English, the literal sense of "to cause to hang by a support from above" is recorded from mid-15c. Related: Suspended; suspending.