がっちり
がっちり · gacchiri · JLPT N1 · adverb
tightly
🧱 Sounds like a hard clamp snapping shut (gatchi), so it means locked tight or solidly built
Gacchiri is onomatopoeia for a firm click of something locking into place. Japanese uses it for both a tight grip and a sturdy build, such as a brick wall.