intermediate (v.)
c. 1600, "to interfere;" 1620s, "to mediate," from inter- "between" + mediate (v.). Related: Intermediated; intermediating.
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").