This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. The act of abutting.

n. The butting or boundary of land, particularly at the end; a headland.

n. That part of a piece of land which abuts on or is contiguous to another; a boundary; a line of contact: used mostly in the plural.

n. The fact of abutting or of lying contiguous: as, the abuttal of the land on a highway.

"Just like in ordinary algebra, it's often also written with abuttal or using the star operator, ie. ab and a*b might both represent a ` mappend ` b."

headland