Following are all the impassive like words, in the list below.
EXPRESSIONLESS
100% like impassive
UNEMOTIONAL
100% like impassive
UNCOMMUNICATIVE
100% like impassive
INCOMMUNICATIVE
100% like impassive
UNEXPRESSIVE
100% like impassive
DEADPAN
99.99% like impassive
POKER-FACED
99.98% like impassive
STOLID
99.97% like impassive
APATHETIC
66.72% like impassive
UNCONCERNED
66.72% like impassive
INDIFFERENT
66.72% like impassive
UNMOVED
66.72% like impassive
UNRESPONSIVE
66.72% like impassive
EMPTY
66.72% like impassive
PASSIVE
66.71% like impassive
QUIET
66.7% like impassive
STOIC
66.36% like impassive
EMOTIONLESS
33.44% like impassive
INEXPRESSIVE
33.44% like impassive
IMPERTURBABLE
33.44% like impassive
STOICAL
33.44% like impassive
UNMOVING
33.44% like impassive
IMPLACABLE
33.44% like impassive
ALOOF
33.44% like impassive
UNIMPASSIONED
33.44% like impassive
UNSMILING
33.44% like impassive
TACITURN
33.44% like impassive
AFFECTLESS
33.44% like impassive
SULLEN
33.44% like impassive
MOTIONLESS
33.44% like impassive
UNRUFFLED
33.44% like impassive
INSCRUTABLE
33.44% like impassive
IMPASSIONATE
33.44% like impassive
UNSPEAKING
33.44% like impassive
UNFLAPPABLE
33.44% like impassive
PASSIONLESS
33.44% like impassive
UNFEELING
33.44% like impassive
IMPERIOUS
33.44% like impassive
PITILESS
33.44% like impassive
UNBLINKING
33.44% like impassive
UNDEMONSTRATIVE
33.44% like impassive
UNSYMPATHETIC
33.44% like impassive
PLACID
33.44% like impassive
UNINTIMIDATED
33.44% like impassive
UNYIELDING
33.44% like impassive
PHLEGMATIC
33.44% like impassive
UNCOMPREHENDING
33.44% like impassive
DISPASSIONATE
33.44% like impassive
UNINFLECTED
33.44% like impassive
OBDURATE
33.44% like impassive
DISINTERESTED
33.44% like impassive
UNAPPROACHABLE
33.44% like impassive
UNPERTURBED
33.44% like impassive
UNFLUSTERED
33.44% like impassive
SPHINXLIKE
33.44% like impassive
DEMEANOUR
33.44% like impassive
IMPLACABILITY
33.44% like impassive
LACONIC
33.44% like impassive
AFFABLE
33.44% like impassive
DISDAINFUL
33.44% like impassive
UNFAZED
33.44% like impassive
TACITURNITY
33.44% like impassive
GLOWERING
33.44% like impassive
STONILY
33.44% like impassive
BEMUSED
33.44% like impassive
UNFLINCHING
33.44% like impassive
ACQUIESCENT
33.44% like impassive
SILENT
33.44% like impassive
STOLIDITY
33.44% like impassive
AWESTRICKEN
33.44% like impassive
INSCRUTABLY
33.44% like impassive
SUPERCILIOUS
33.44% like impassive
NONCHALANT
33.44% like impassive
FRIGIDLY
33.44% like impassive
UNAFFECTED
33.44% like impassive
UNCARING
33.44% like impassive
EXPRESSIONLESSLY
33.44% like impassive
DIFFIDENT
33.44% like impassive
GUILELESS
33.44% like impassive
DEFIANT
33.44% like impassive
UNCHANGING
33.44% like impassive
STOLIDLY
33.44% like impassive
GLUM
33.44% like impassive
SATURNINE
33.44% like impassive
UNADORNED
33.44% like impassive
GLOWER
33.44% like impassive
UNEMPHATIC
33.44% like impassive
COLDLY
33.44% like impassive
REMORSELESS
33.44% like impassive
UNAFFECTING
33.44% like impassive
UNWINKING
33.44% like impassive
UNASSERTIVE
33.44% like impassive
CONTEMPTUOUS
33.44% like impassive
DOWNCAST
33.44% like impassive
LIFELESS
33.44% like impassive
COMPASSIONLESS
33.44% like impassive
UNAFFECTIONATE
33.44% like impassive
MASKLIKE
33.44% like impassive
UNAWED
33.44% like impassive
GRUFF
33.44% like impassive