постоянный

1) General subject: Sustainable, abiding, all-time, assiduous, blue, certain, changeless, chronic, constant, continual, continuous (о токе), enduring, (в сложных словах имеет значение) ever, everlasting, fixed, hourly, immanent, in ordinary, incessant, invariable, invariant, irremovable, lasting, never failing, never-failing, ongoing, perdurable, permanent, perpetual, persistent, resident (о населении и т.п.), sartin, sedentary, sedulous, self consistent, self-consistent, settled, stable, standing, stationary, steadfast, steady, true as the needle to the pole, undeviating, undying, uniform, unremitted, unvaried, unvarying, regular, carved in stone, never-ending, established, long-term, restless

2) Computers: immutable

3) Geology: persistent (о минерале или месторождении)

4) Colloquial: eternal, inevitable

5) Engineering: flat (о величине), sustained

6) Bookish: substantive, timeless

7) Rare: invaried

8) Mathematics: continued

9) Railway term: dead

10) Accounting: running, set (напр. о ценах), unchangeable

11) Linguistics: sortal

12) Automobile industry: non-fluctuating

13) Architecture: ever-present

14) Diplomatic term: on-going

15) Telecommunications: always-on

16) Abbreviation: perm

17) Electronics: direct, fixed-time

18) Information technology: consistent, hard, non-alterable

19) Banking: set (о ценах)

20) Business: firm

21) Drilling: const. (constant)

22) Network technologies: fxd

23) Automation: solid, standing (напр. о файле), uniform (напр. о величине перемещения, скорости)

24) Quality control: level, steady (во времени)

25) Arms production: fixed (о заряде)

26) Makarov: chronical, continuing, direct (о токе), frequent, imperishable, nonvolatile, quiescent, specified, steady-state, tireless, true blue, uniform (о скорости), uniform (по объёму или по площади)

27) Gold mining: perennial