| fast(adjective, adverb, firm, thoroughly, strongly) |
| firmly(adverb, firm, sharply, solidly, tightly) |
| securely(adverb, hard, firm, thoroughly, strongly) |
| steadily(adverb, hard, firm, closely, strongly) |
| intently |
| decidedly |
| motionlessly(adverb, severely, thoroughly, strongly, firmly) |
| persistently(adverb, permanently) |
| staunchly(adverb, firmly, definitely, obstinately, stubbornly) |
| tenaciously(adverb, firm, firmly, obstinately, stubbornly) |
| tight(adjective, adverb, hard, firm, thoroughly) |
| tightly(adverb, hard, firm, thoroughly, strongly) |
| beyond shadow of doubt(expression, idiom, adverb, absolutely, certainly) |
| come what may(expression, idiom, adverb, absolutely, certainly) |
| constantly(adverb, permanently) |
| determinedly |
| earnestly |
| enduringly(adverb, severely, thoroughly, strongly, firmly) |
| firm(hard, firmly) |
| inexorably(adverb, absolutely, certainly, clearly, definitely) |