Uninterrupted in time and indefinitely long continuing; SYN. constant, incessant, never-ending, perpetual, unceasing, unremitting.

ETYM Latin continuus, from continere to hold together. Related to Continent.
1. Continuing in time or space without interruption; SYN. uninterrupted.
2. (Mathematics) Of a function or curve; extending without break or irregularity.

ETYM Latin incessans, -antis; pref. in- not + cessare to cease: cf. French incessant. Related to Cease.
Occurring so frequently as to seem ceaseless or uninterrupted; SYN. perpetual, endless.

ETYM Latin permanens, -entis, p. pr. of permanere to stay or remain to the end, to last; per + manere to remain: cf. French permanent. Related to Per-, and Mansion.
1. Continuing or enduring without marked change in status or condition or place; SYN. lasting.
2. Not capable of being reversed or returned to the original condition.

1. Not easily excited or upset
2. Not subject to change or variation especially in behavior
3. Securely in position; not shaky