Fugacious
Fugacious , adjective
[Latin fugax, fugacis, from fugere: compare French fugace. See Fugitive.]
1.
Flying, or disposed to fly; fleeing away; lasting but a short time; volatile.
Much of its possessions is so hid, so fugacious, and of so uncertain purchase.
2.
(Biology) Fleeting; lasting but a short time; -- applied particularly to organs or parts which are short-lived as compared with the life of the individual.