Luokka Etuliitteetbulgariaenglantiespanjaesperantohollantiitaliajapanikreikkalatinalatvialiettuanorjaportugalipuolaranskaruotsisaksasuomitanskaturkkitšekkiunkarivenäjäviro

noso- nucleo- nyct- O' ob- ochl- oct- octa- octakis- octo- oculo- odonto- oeno- Of- off- oleo- oligo- omni- omo- omphalo- on- onco- oneir- oneiro- onto- onycho- oo- ophid- ophio- ophthalmo- opto- or- organo- ornith-

ornitho- oro- orth- ortho- osmio- osseo- ossi- osteo- ot- oto- out- over- ovo- oxal- oxalo- oxi- oxo- oxy- pachy- paedo- palae- palaeo- palato- pale- paleo- pali- palladio- pan- Pan- pano- pant- panta- panto-

papa- para- pari- parthen- partheno- path- patho- patr- patri- pauci- pebi- pedo- peloro- pen- pene- pent- penta- pentakis- pentaprismo- per- perfluoro- peri- perma- peroxy- peta- petro- phago- pharmaco- pharyngo- pheno- phil- philo- phlebo-