| standby(noun, control, duty, reliable, responsible) |
| staunchest(adjective, duty, reliable, effective, responsible) |
| steadfast(adjective, duty, reliable, effective, responsible) |
| steady(adjective, duty, reliable, effective, responsible) |
| steady-going(expression, duty, reliable, effective) |
| substantial(adjective, duty, reliable, effective, responsible) |
| sure(adjective, test, expert, reliable) |
| surefire(adjective, duty, reliable, effective, responsible) |
| tested(adjective, test, expert, reliable) |
| time-tested(adjective, duty, reliable, effective, responsible) |
| tip-top(adjective, best, better, reliable, responsible) |
| tried-and-true(adjective, test, expert, reliable) |
| tried and tested(adjective, test, expert, reliable) |
| trouble-free(adjective, duty, reliable, effective, responsible) |
| trouble-proof(adjective, duty, reliable, effective, responsible) |
| troubleproof(adjective, duty, reliable, effective, responsible) |
| true(adjective, duty, reliable, effective, responsible) |
| trust-worthy(adjective, duty, reliable, effective, responsible) |
| trustworthy(adjective, duty, reliable, effective, responsible) |
| unfailing(adjective, expert, reliable, dependable) |