A — 1: μύλος
(Strong's #3458 — Noun Masculine — mulos — moo'-los )

denotes "a handmill," consisting of two circular stones, one above the other, the lower being fixed. From the center of the lower a wooden pin passes through a hole in the upper, into which the grain is thrown, escaping as flour between the stones and falling on a prepared material below them. The handle is inserted into the upper stone near the circumference. Small stones could be turned by one woman (mill-grinding was a work deemed fit only for women and slaves; cp. Judges 16:21 ); larger ones were turned by two (cp. Matthew 24:41 , under MILL), or more.

Matthew 18:6Mark 9:42 Luke 17:2Revelation 18:22
B — 1: μυλικός
(Strong's #3457 — Adjective — mulikos — moo-lee-kos' )

"of a mill," occurs in Luke 17:2 (see above).

B — 2: μύλος
(Strong's #3458 — Noun Masculine — mulinos — moo'-los )

"made of millstone," is used with lithos, "a stone;" and with the adjective megas, "great," in the best mss. in Revelation 18:21 (some have the word mulos; see A).