interminable (adj.)

• ageless
• all-inclusive
• articulated
• boundless
• ceaseless
• connected
• constant
• continual
• continued
• continuing
• continuous
• countless
• cyclical
• dateless
• direct
• drawn-out
• endless
• eternal
• everlasting
• extended
• extensive
• far-flung
• featureless
• illimitable
• immeasurable
• immediate
• immemorial
• immense
• incalculable
• incessant
• incomprehensible
• indestructible
• inexhaustible
• infinite
• innumerable
• joined
• lasting
• lengthened
• lengthy
• limitless
• linked
• long
• long-winded
• longish
• measureless
• monotonous
• never-ending
• nonstop
• perdurable
• perennial
• periodic
• permanent
• perpetual
• prolonged
• protracted
• recurrent
• repetitive
• round-the-clock
• running
• seamless
• sempiternal
• serried
• sesquipedalian
• smooth
• stable
• steady
• straight
• tall
• timeless
• unbounded
• unbroken
• unceasing
• undifferentiated
• unending
• unfathomable
• uniform
• uninterrupted
• universal
• unlimited
• unmeasurable
• unmeasured
• unnumbered
• unplumbed
• unrelieved
• unremitting
• untold