spend- / Indo-European roots
To make an offering, perform a rite, hence to engage oneself by a ritual act.O-grade from *spond-.
1. Suffixed form *spond-eyo-. sponsor, spouse; despond, espouse, respond from Latin spondēre, to make a solemn promise, pledge, betroth.
2. Suffixed form *spond-ā-. spondee from Greek spondē, libation, offering.
[Pokorny spend- 989.]