a·vail 
(
ə-v
āl
)
v. a·vailed, a·vail·ing, a·vails
v.tr. To be of use or advantage to; help: Nothing could avail the dying patient.
v.intr. To be of use, value, or advantage; serve: Halfway measures will no longer avail.
n. Use, benefit, or advantage: labored to no avail.
Idiom: avail (oneself) of To make use of.
[Middle English availen : a-, intensive pref. (from Latin ad-; see AD-) + Old French valoir, vail-, to be worth (from Latin valēre, to be strong; see wal- in the Appendix of Indo-European roots).]
a·vailing·ly adv.