In this work we review different etymological theories and try to determine the semantic development of the ethymologically unclear West Slavic word *katъ — ‘executioner; hangman’. The aim of the article is to give new arguments that will prove the connection, postulated by some researchers, between the word *katъ and the ProtoSlavic *katati — the form that was not saved in the West Slavic area and is the iterative form of *kotiti. The basic difficulty in the reconstruction the Proto-Slavic form of this word is a lack of its designate in the Proto-Slavic reality (e.g. the function of the hangman started to exist in Poland only with appearance of the Magdeburg Law). The paralel with the lat. tortor — ‘tormentor, hangman’ connected with the word torqueō — ‘to spin, to rotate, to torture’ does not seem to be convincing as well. An important role in the trial of establishing the semantic development of the word is to compare it to the numerous derivates made as well from West Slavic *katъ, eg. Czech. katan — ‘rude man’, katiti se — ‘to be angry’, katiti se do něč. — ‘to act with engagement, effort’ etc. as from derivates made from the verb *katati, eg. Russ. катáть — ‘to beat, to punish orally or corporaly’, кáтка ‘flogging, corporal punishment’ and related *katjati, Russ. Качáть — ‘to move, to wave in the air ’, восточно-польских czech. káceti ‘to knock down’. West Slavic *katъ is nomen actionis (which then became nomen agentis) made from *katati which meant the rapid movement. The meaning of this verb later became more concrete starting to mean ‘to beat, to torment’.