Synonyms of insidiously
- 2 Syllables
- slyly, quietly, hush-hush
- 3 Syllables
- stealthily, privily, secretly, craftily, shiftily, covertly
- 4 Syllables
- furtively, privately, unobserved, obscurely, personally
- 5 Syllables
- surreptitiously, confidentially, clandestinely, intimately, underhandedly