The word "polster" is a German term that refers to a cushion or a pillow. In IPA (International Phonetic Alphabet), it is spelled as /ˈpɔl.stɐ/. The initial sound is a voiceless bilabial plosive /p/, followed by an open-mid back rounded vowel /ɔ/. The letter "l" is pronounced as /l/, while the final sound is a voiceless alveolar fricative /s/. The letter "t" at the end is not pronounced, as it is used to represent the German noun declension.
The word "polster" originates from the German language. It is derived from the Middle High German word "bolster", which in turn comes from the Old High German "polstar". The term ultimately traces back to the Old English word "bollster" or "bolster", meaning a pillow or cushion. From Old English, it made its way into Middle English and then into German, where it acquired the form "polster" with a slightly altered meaning, referring to a cushion or padding used in upholstery.