1) Gently 2) In a quiet manner 3) In silence 4) Inaudibly 5) Mutely 6) Sans sound 7) Softly 8) Soundlessly 9) Taciturnly 10) Without a peep 11) Without a sound 12) Without a word 13) Without attracting attention 14) Without noise 15) Without speaking 16) Wordlessly Found on https://www.crosswordclues.com/clue/silently
silently 1. Marked by absence of noise or sound; still. 2. Not inclined to speak; not talkative. 3. Unable to speak. 4. Refraining from speech. 5. Not voiced or expressed; unspoken: a silent curse; silent consent. 6. Inactive; quiescent: a silent volcano. 7. Linguistics: Having no phonetic value; unpronounced; such as, the silent b in subtle. 8.... Found on http://www.wordinfo.info/words/index/info/view_unit/3592/