perennial (n.)
- aged
- amphibian
- ancient
- angiosperm
- annual
- antique
- biennial
- chattering
- constant
- cosmopolite
- cutting
- cyclical
- dicot
- dicotyledon
- ephemeral
- eternal
- evergreen
- everlasting
- fungus
- gametophyte
- gymnosperm
- hardy
- hydrophyte
- immortal
- lasting
- monocot
- nonstop
- old
- permanent
- plant
- rapid
- regular
- running
- seedling
- smooth
- spermatophyte
- sporophyte
- stable
- steady
- straight
- thallophyte
- tough
- triennial
- uniform
- vegetable
- vital
- weed
perennial (adj.)
- abiding
- aged
- amphibian
- ancient
- annual
- antique
- articulated
- biennial
- ceaseless
- chronic
- connected
- constant
- continual
- continued
- continuing
- continuous
- cutting
- cyclical
- deciduous
- direct
- durable
- endless
- enduring
- ephemeral
- eternal
- evergreen
- everlasting
- exotic
- featureless
- half-hardy
- hardy
- immediate
- immortal
- immutable
- imperishable
- incessant
- interminable
- inveterate
- joined
- lasting
- lifelong
- linked
- long-lasting
- long-lived
- long-standing
- long-term
- macrobiotic
- monotonous
- never-ending
- nonstop
- old
- oscillating
- perdurable
- periodic
- permanent
- perpetual
- persistent
- persisting
- rapid
- recurrent
- regular
- remaining
- repeated
- repetitive
- round-the-clock
- running
- seamless
- sempiternal
- serried
- smooth
- stable
- staccato
- steadfast
- steady
- straight
- sustained
- timeless
- tough
- triennial
- unbroken
- unceasing
- unchanging
- undifferentiated
- undying
- unending
- unfading
- unfailing
- uniform
- uninterrupted
- unrelieved
- unremitting
- unvarying
- vital
