The spelling of the word "oyler" can be explained using IPA phonetic transcription. In IPA, the word is spelled as /ˈɔɪlər/. The first sound is an "oy" diphthong, which is a combination of the "o" and "i" sounds. The next sound is a clear "l" sound, followed by an "uh" vowel sound. This pronunciation reflects the origins of the word, which is most likely based on the verb "to oil," and refers to someone who works with or sells oil.