noun
square nail; square peg
Refers to a nail or peg with a square cross-section, used in traditional woodworking and construction. The 'square peg' gloss is a direct translation but less common in everyday English; the primary meaning is a square nail.
古い建物の修理には角釘が使われることがある。
Square nails are sometimes used in the repair of old buildings.
丸釘 is a round nail, the more common modern type, while 角釘 is a square nail used in traditional contexts.
Compound of 角 (かく, 'square') and 釘 (くぎ, 'nail'). The reading is a straightforward combination of the on'yomi of 角 and the kun'yomi of 釘.