Probably cm. At least the Latin abbreviations are used in school http://ebooks.edu.gr/modules/ebook/show.php/DSGYM-B200/530/3508,14387/
Futher information: εκατοστόμετρο, το = εκατοστός (1/100:th) + μέτρο came into Greece in 1831 as a translation of the Fr. centimétre. Later it got the shortened synonym εκατοστό, το.
εκατοστόγραμμο, το came 1883 fr. Fr centigramme and εκατοστόλιτρο, το came in 1891 fr. Fr. centilitre. They are of course never shortened to εκατοστό
Hm. That is strange. Πόντος/Pontos also was the name of a country in the north of Turkey, along the coast of the Black sea. The scandinavians called this land Asagartia. The romans conquered Pontos about 60 years before Yeshua was born, and emigrants from Pontos even reached Scandinavia, and where they today is incorporated in Norwegian mythology, called "aeser"(asagartians). What does the word ποντος litarally mean?
Duo's πόντος,ο is 1)cm (colloquial) 2. a measure unit for length, generally 3. point in games 4. knitting stitch < Venetian ponto/ peak, nose
Your very interesting remark concerns probably the other πόντος, ο = the open sea. In old Greek it meant a passage in the sea, (Ελλής-ποντος/ Hellespont, Εύξεινος Πόντος/ Black Sea) < I.E. pent-/ go, walk < Sanscrit pánthâb/ way (Fr. pont, Sp. puente)