1A ladder — a tool made of two long rails joined by evenly spaced rungs, used to climb up and down. Common in roof repair, fruit picking, firefighting, and any task requiring vertical reach. The kanji 梯 in 梯子 is non-jōyō, so the word is usually written in kana (はしご or ハシゴ) in modern Japanese.
屋根の上の落ち葉を取るために、はしごをかけた。
I propped up a ladder to clear the fallen leaves off the roof.
はしごの一番上の段に立つのは危ないからやめなさい。
Don't stand on the top rung of the ladder — it's dangerous.
消防車のはしごが高く伸びて、ビルの上階まで届いた。
The fire truck's ladder extended high up to reach the upper floors of the building.
リンゴの収穫期は、はしごを使って木の上の方の実を採る。
During apple harvest season, we use ladders to pick the fruit higher up in the trees.
2A steep, narrow, near-vertical staircase — the kind found on ships, in lofts, or leading to attics. Closer to a ladder than to a proper staircase (階段). Used in phrases like 船のはしご (a ship's ladder) and 屋根裏に上がるはしご (the ladder up to the attic).
ヨットの船室に降りるには急なはしごを使う。
You use a steep ladder-stair to descend into the yacht's cabin.
ロフトに上がるはしごが急すぎて、子どもには危ない。
The ladder to the loft is too steep, so it's dangerous for children.
3(Colloquial) Going from one place to another in succession — typically barhopping or visiting multiple eateries, cafés, or shops one after another. Used as a verb: 居酒屋をはしごする, カフェをハシゴする. The set phrase はしご酒 / ハシゴ酒 (going from bar to bar drinking) is especially common. Hiragana はしご and katakana ハシゴ are both standard; katakana feels slightly more casual or conversational.
金曜の夜、同僚と居酒屋を三軒はしごした。
On Friday night I went barhopping through three izakayas with my coworkers.
今日は気になっていたカフェをハシゴして、デザートを食べ比べた。
Today I hit up several cafés I'd been curious about and compared their desserts.
終電を逃すほどハシゴ酒をしてしまった。
We barhopped so much we ended up missing the last train.
彼は二次会、三次会とはしごするのが好きだ。
He loves carrying on from the after-party to the after-after-party.