ˈentəsə̇s noun
( plural enta·ses -əˌsēz)
Etymology: Greek, literally, distention, stretching, from enteinein to stretch tight (from en- en- (II) + teinein to stretch) + -sis — more at thin
: a slight convexity (as in the shaft of a column) ; especially : one that begins at the base of a shaft and continues to the top and that is greatest a little below the middle point
the entasis of the columns at the corner of the peristyle — Vincent Sheean