undeveloped
unexploited
extra
fresh
held back
held in reserve
held out
in abeyance
in hand
mint
new
original
pristine
put aside
put by
reserve
saved
spare
stored
suspended
to spare
unapplied
unbeaten
unconsumed
unemployed
unexercised
unexpended
unhandled
unspent
unspoiled
untouched
untrodden
unused
unutilized
virginal
waived
event-related
exhaustless
geothermal
limitless
nonexistent
onshore
recoverable
renewable
stored-up
unattained
unattempted
uncharted
uncollected
undescribed
undisclosed
undiscovered
undreamed-of
unnoted
unpopulated
unrealized
unrevealed
untested
adapt
apt
capped
clapped
entrapped
flapped
kept
lapped
mapped
napped
rapped
rapt
recapped
sapped
scrapped
slapped
snapped
strapped
tapped
trapped
unwrapped
wrapped
zapped