Following are all the sextennial like words, in the list below.
SEPTENARY
100% like sextennial
VICENNIAL
100% like sextennial
QUINDECENNIAL
100% like sextennial
PLURENNIAL
100% like sextennial
YEARSLONG
100% like sextennial
QUADRENNIAL
100% like sextennial
PLURIENNIAL
100% like sextennial
TRIENNIAL
100% like sextennial
MULTIYEAR
100% like sextennial
LONG-LASTING
100% like sextennial
PERMANENT
100% like sextennial
PERPETUAL
100% like sextennial
EXTENDED
100% like sextennial
EVERLASTING
100% like sextennial
ONGOING
100% like sextennial
PERENNIAL
100% like sextennial
DURATIVE
100% like sextennial
ETERNAL
100% like sextennial
LASTING
100% like sextennial
LIFELONG
100% like sextennial
CAREERLONG
100% like sextennial
ONHOLDING
100% like sextennial
ABIDING
100% like sextennial
FOREVER
100% like sextennial
LONG-LIVED
100% like sextennial
LONG-RANGING
100% like sextennial
ENDURING
100% like sextennial
LONG-STANDING
100% like sextennial
EVERGOING
100% like sextennial
LONG-PENDING
100% like sextennial
DRAWN OUT
100% like sextennial
PERPETUABLE
100% like sextennial
INTERMINABLE
100% like sextennial
CONTINUANT
100% like sextennial
LASTABLE
100% like sextennial
STANDING
100% like sextennial
CO-ENDURING
100% like sextennial
LONG-TERM
100% like sextennial
INDISSOLUBLE
100% like sextennial
TENURED
100% like sextennial
LIVELONG
100% like sextennial
ONE-YEAR-OLD
100% like sextennial
FINAL
100% like sextennial
DURABLE
100% like sextennial
PLURIANNUAL
100% like sextennial
AGELESS
100% like sextennial
SET FOR LIFE
100% like sextennial
PROLONGABLE
100% like sextennial
SEQUENT
100% like sextennial
FOR THE AGES
100% like sextennial
YEAR-ROUND
100% like sextennial
PERMANABLE
100% like sextennial
CONTINUABLE
100% like sextennial
EXPIRING
100% like sextennial
LONG-RUNNING
100% like sextennial
TIMEPROOF
100% like sextennial
PROVISORY
100% like sextennial
IRREVERSIBLE
100% like sextennial
LIVED
100% like sextennial
ULTRAPERMANENT
100% like sextennial
COTERMINOUS
100% like sextennial
TEMPORAL
100% like sextennial
TERMINABLE
100% like sextennial
LONG FOR
100% like sextennial
PROVISIONAL
100% like sextennial
PERDURABLE
100% like sextennial
LONG-ESTABLISHED
100% like sextennial
QUINTENARY
100% like sextennial
SUBSTANTIVE
100% like sextennial
SENATORIAL
100% like sextennial
PROBATORY
100% like sextennial
IMMARCESCIBLE
100% like sextennial
CONTINUAL
100% like sextennial
SUSTENTIVE
100% like sextennial
ULTIMATE
100% like sextennial
COEXTENSIVE
100% like sextennial
TERMINATIONAL
100% like sextennial
RECURRING
100% like sextennial
LAST
100% like sextennial
DETERMINABLE
100% like sextennial
INDELIBLE
100% like sextennial
ETERMINABLE
100% like sextennial
SUBSISTENT
100% like sextennial
STICKTOITIVE
100% like sextennial
INDEFEASIBLE
100% like sextennial
TERMINATED
100% like sextennial
STILL
100% like sextennial
IMPERISHABLE
100% like sextennial
TENSIBLE
100% like sextennial
SCEPTRAL
100% like sextennial
WELL-ESTABLISHED
100% like sextennial
CONTEMPORANEOUS
100% like sextennial
ENDURABLE
100% like sextennial
CONTINGENT
100% like sextennial
VITAL
100% like sextennial
EVENTUAL
100% like sextennial
PROTRACTABLE
100% like sextennial
PERSEVERANT
100% like sextennial
SUSTAINABLE
100% like sextennial
INCESSABLE
100% like sextennial