固(かた)まるto harden, to solidify, to become firm, to become certain, to gather (together), to assemble, to huddle together

粘土(ねんど)が乾燥(かんそう)して固(かた)まりました。

The clay has dried and hardened. {to harden, to solidify, to become firm, to become certain, to gather (together), to assemble, to huddle together}

駅(えき)の前(まえ)には多(おお)くの居酒屋(いざかや)が固(かた)まっている。

There are many pubs clustered in front of the station. {to harden, to solidify, to become firm, to become certain, to gather (together), to assemble, to huddle together}

基礎(きそ)が固(かた)まったので、応用(おうよう)の問題(もんだい)を解(と)きたいです。

Since I have solidified the basics, I want to solve application problems. {to harden, to solidify, to become firm, to become certain, to gather (together), to assemble, to huddle together}

狭(せま)い歩道(ほどう)で多(おお)くの人(ひと)と固(かた)まって歩(ある)いてはなりません。

You must not walk in a huddled group with many people on a narrow sidewalk. {to harden, to solidify, to become firm, to become certain, to gather (together), to assemble, to huddle together}

これはマグマが冷(ひ)やされて固(かた)まったもの、いわゆる溶岩(ようがん)である。

This is something that has been cooled and solidified from magma, also known as lava. {to harden, to solidify, to become firm, to become certain, to gather (together), to assemble, to huddle together}