Er and Exclamation

Er noun - A trivalent metallic element of the rare earth group; occurs with yttrium.

Exclamation and er are semantically related in emphatic exclamation topic. In some cases you can use "Exclamation" instead a noun "Er".

Exclamation noun - An abrupt excited utterance.

Er and exclamation are semantically related in boo topic. Sometimes you can use "Er" instead a noun "Exclamation", if it concerns topics such as wow.