noun
lump of iron; iron mass; iron ingot
Refers to a solid piece or mass of iron, often unworked or raw. Can be used literally or figuratively to describe something very hard or heavy.
工場の前に大きな鉄の固まりが置いてあった。
A large lump of iron was placed in front of the factory.
この機械は鉄の固まりのように重い。
This machine is as heavy as a lump of iron.
鉄塊 is a more technical term for an iron ingot or block, often used in metallurgy, while 鉄の固まり is a more everyday description of a lump or mass of iron.
Compound of 鉄 (てつ, 'iron') + の (possessive particle) + 固まり (かたまり, 'lump, mass'). The reading てつ is the on'yomi of 鉄, and かたまり is the nominalized form of the verb 固まる (かたまる, 'to harden, solidify').