titter
Concise Oxford English Dictionary © 2008 Oxford University Press:
titter/ˈtɪtə(r)/
▶noun a short, half-suppressed laugh. ▶verb give a titter.
– derivatives
titterer noun,
tittering noun & adjective,
titteringly adverb.
titterer noun,
tittering noun & adjective,
titteringly adverb.
– origin C17: imitative.
'titter' also found in these Oxford entries:

