origin: origino (cf. fonto); -al: (adj.) -ala (cf. stranja); (person) -alo, stranj-ulo; (first of things) -al-ajo; -ality: (quality, object) -al-eso, -al-ajo; -ally: origine, komence, unesme.
originate: (tr.) naskigar; produktar; inventar; iniciar; genitar; (intr.) (de-)venar, naskar, komencar, havar origino en o de; (cf. decendar).
origination: genit-(ad)o, kre-(ad)o, origino; (intr.) nasko.
originator: genit-anto, autoro, prima kauzo.
oriole: oriolo.
orison: prego.
ornament: ornar (ulo, ulu, su, per ulo) (cf. ornament-izar, dekorar, plu-bel-igar).
ornament: (n.) orn-ivo, ornamento; -al: ornament-ala (design-uro, e.c.); -ation: ornament-izo, -aro.
ornate: orn-ita, bela, eleganta.
ornithology: ornitologio.
ornithopter: ornitoptero.
orography: orografio.
orphan: orfan-a; -(ul)o; -age: -erio; -ed: -ig-ita.
orpiment: orpimento.
orris-root: irido-radiko.
orthocenter (centre): ortocentro.
orthochromatic: ortokroma.
orthodox: ortodoxa, (person) -(ul)o; -y: -eso.
orthoepy: korekta pronunc-ado.
orthogenesis: ortogenezo.
orthogonal: ort-angula.
orthography: ortografio; -phic: -ala.
orthopedics: ortopedio.
orthopteran: ortoptero; -ous: -a.
ortolan: ortolano.
orvet: orveto.
orvietan: orvietano.
oscillate: (intr.) ocil-ar (cf. vibrar, fluktuar); (tr.) -igar.
osculate: (geom.) (tr., intr.) oskular (kiss) kisar.
osier: oziero.
osmium: osmio.
osmosis: osmoso.
osprey: osifrago.
osseous: ost-a, -ala, -oza.
ossify: ost-igar (ulo), -eskar, -ifar.
ostensible: apar-anta, sembl-anta, asert-ita.
ostensorium: ostensorio.
ostentation: ostento, -ado, -em-eso.
ostentatious: ostent-anta, -oza, -ema; to be o.: -ar (cf. lux-oza, pomp-oza).
osteology: osteologio.
osteoma: osteomo.
ostitis: ostito.
ostler: kaval-ala serv-isto.
ostracism: ostracismo.
ostracize: exkluzar ostracisme, ostracism-igar, -eskar.
ostrich: strucho; o. feather: -o-plumo.
Ostrogoth: ostrogoto.
otalgia: otalgio.
otary: otario.
other: altr-a; the o.s: l’altri, la ceteri; every o.: (ye) omna du-esma; each o.: l’una l’altra; (of many) l’uni l’altri; o.wise: altre.
otolith: otolito.
otitis: otito.
otter: lutro.
otto of roses: roz-esenco.
ottoman: (divan) otomano.
ought: devar (cf. darfar, debar, mustar).
ounce: (animal) unco; (weight) 28,35 grami.
our: nia; ours: le nia (as in: their things are better than ours); nia (as in: that is no business of ours; to ne esas nia afero); ourselves: ni (ipsa).
oust: ek-, for-pulsar (ulu, de, ek) (cf. suplantar); (legal) eviktar, desposed-igar (ulu).
out: (gen. sense) ek; (outside) exter(e); (away) for; (beyond, past) preter; (disclosed) konoc-ata; (extinct) exting-ita; (at an end) exhaust-ita, konsum-ita; fin-ita; (cf. prefix par-); (without) sen; (loudly) laute; (thoroughly) par-; (hired or rented) lug-ita; (puzzled) embaras-ata; (in error) des-, nejusta, ne-exakta; (of books) vend-ata, apar-inta, imprim-ita; o. with him: ek pulsez il; extere! o. with it: informez ni! dicez lo! I am o. of salt: me ne havas plusa salo; me esas sen salo; la salo mankas; o. of pocket: perdar; drink o. of a glass: drinkar ek glaso; be o. of countenance: konfuz-eskar; read o. of a book: lektar de (od, en) libro; to come o.: ek-irar, irar ek; (first appearance) debutar; o. of money: sen pekunio; o. and o.: perfekta, kompleta; o. of hatred: pro odio (ad ulu); o. of charity: por (od, pro) karitato; o. of favo(u)r: des-favor-iz-ita; o. of place: (misplaced) diplas-ita; (unbecoming) nekonven-anta, ne-oportuna; (unemployed) sen-employa; o. of sight: ne-vid-ebla; to be o. at sea: esar en la meza o larja maro; o. of humo(u)r: despitar; esar en mala humoro; to squeeze o.: ek-prisar; o. of danger: ek-irar o eskapir la danjero; to sing o. of tune: kantar ne-juste o ne-akorde; o. of sight, o. of mind: for la vido, for la mento; the fire is o.: la fairo esas exting-ita; the cask is o.: la barelo esas vakua; the book is o. of print: l’edituro exhaust-esis; o. of use: ne-uz-ata; she laughed right o.: el rid-eskis, el ridis laute; I found you o.: me des-kovris vu; o. of hand: (unmanageable) ne-guvern-ebla; o. of order: (physically) malad(et)a; ne-sana; trubl-ita; o. of the way: (extraordinary) extraordinara.
outbalance: plu multe pezar, inklin-igar la balanco; determinar la decido; dominacar; vinkar.
outbid: aucinar, ofrar plu alta preco, super-ofrar.
outbreak: explozo, sedicio, revolto; (of epidemics) erupto, invado.
outbuilding: extera konstrukturo o dom-eto; barako; anexo-domo; hangaro.
outcast: ek-puls-ita, -ito; proskript-ito, exil-ito; exkluz-ito.
outcome: rezulto, -ajo; konsequ-ant-ajo.
outcry: klam-(ad)o; (scream) krio.