composed
balanced
bovine
collected
constant
cool
dispassionate
dull
easy
even-keeled
even-tempered
fast
fiducial
firm
firm as Gibraltar
fixed
flinty
immovable
impassive
imperturbable
in equilibrium
inexcitable
inflexible
inirritable
loyal
nonchalant
patient
predictable
relaxed
reliable
secure
set
settled
solid
sot
sound
stable
staunch
steadfast
steady
steely
stoic
stolid
substantial
true
unbending
undeflectable
undisturbable
disyllabic
ebullient
emotionless
flabbergasted
irreconcileable
off-limits
self-assured
self-poised
self-sustained
tightfisted
unbreathing
unconvinced
undependable
unemotional
uninterested
unperturbed
unreadable
unruffled
unscalable
unselfconscious
unworried
valueless
flappable