disyllable
Concise Oxford English Dictionary © 2008 Oxford University Press:
disyllable /dʌɪˈsɪləb(ə)l, ˈdʌɪsɪl-/ (also dissyllable /dɪˈsɪləb(ə)l/)
▶noun Prosody a word or metrical foot consisting of two syllables.
– derivatives
disyllabic /ˌdʌɪsɪˈlabɪk/ adjective.
disyllabic /ˌdʌɪsɪˈlabɪk/ adjective.
– origin C16: alt. (influenced by syllable) of Fr. disyllabe, via L. from Gk disullabos ‘of two syllables’.
'disyllable' also found in these Oxford entries:

