"state or condition of being intermediate," 1713, from intermediate + abstract noun suffix -cy. Intermediateness is from 1826.
Entries linking to intermediacy
intermediate adj.
"being or occurring between" (two things), early 15c., from Medieval Latin intermediatus "lying between," from Latin intermedius "that which is between," from inter "between" (see inter-) + medius "in the middle" (from PIE root *medhyo- "middle").
-cy
abstract noun suffix of quality or rank, from Latin -cia, -tia, from Greek -kia, -tia, from abstract ending -ia (see -ia) + stem ending -c- or -t-. The native correspondents are -ship, -hood.