12-Letter Words Ending: IAL

• A fifth anniversary.

• A five-year period.

• That happens every five years.

• That lasts for five years.

• (of behaviour) having both psychological and social aspects

• having some official authority or sanction

• Governed by expediency; seeking advantage.

• relating to or resulting from experience

• derived from experience or the experience of existence

• not conducive to commercial success

• relating to or showing a difference

• involving or containing one or more derivatives

• the result of mathematical differentiation; the instantaneous change of one quantity relative to another; df(x)/dx

• a quality that differentiates between similar things

• a bevel gear that permits rotation of two shafts at different speeds; used on the rear axle of automobiles to allow wheels to rotate at different speeds on curves

• of or relating to the cells in a sporangium that give rise to spores