The spelling of the word "Osowiec" is pretty straightforward once you know how to pronounce it. In IPA phonetic transcription, it is written as /ɔsɔvʲɛt͡s/. The first sound, /ɔ/, is an open-mid back vowel, similar to the "o" in "hot". The second sound, /s/, is an unvoiced alveolar fricative, like the "s" in "sister". The next sound, /ɔvʲ/, is a bit tricky—it's the combination of an open-mid back vowel and a palatalized labial glide. Finally, the word ends with /ɛt͡s/, which sounds like "ets" but with a slight release of air between the "t" and "s".
The word Osowiec is derived from the Polish language. It is most commonly associated with the village of Osowiec located in northeastern Poland. The etymology of Osowiec originates from the archaic Polish word osów or os which means buckthorn. The suffix -iec is used in Polish to denote a place, so Osowiec can be understood as a place abundant in buckthorn.