hemicylindrical

As adjectives the difference between semicylindrical and hemicylindrical

is that semicylindrical is having the shape of a semicylinder while hemicylindrical is having the form of half a cylinder (divided down its axis.

As a noun cylinder

is a surface created by projecting a closed two-dimensional curve along an axis intersecting the plane of the curve.

As an adjective hemicylindrical is

having the form of half a cylinder (divided down its axis.

As adjectives the difference between half and hemicylindrical

is that half is consisting of a moiety, or half (1/2, 50%) while hemicylindrical is having the form of half a cylinder (divided down its axis).

As an adverb half

is in two equal parts or to an equal degree; in some part approximating a half; partially; imperfectly.

As a noun half

is one of two usually roughly equal parts into which anything may be divided, or considered as divided; — sometimes followed by of; as, a half of an apple.

As a verb half

is to halve.

As a preposition half

is a half-hour after, thirty minutes after (used with the number of the hour).