Proto-Indo-European Roots

Root/Stem: *newo-
Meanings:  new, fresh
Related to: Greek neos (new, young)
Latin novus < *nevos (new) > 
Aromanian nawe, French nouveau, Spanish nuevo, Sardinian novu, nou, Occitan nouveu, Catalan nou, Italian nuovo, Rhaeto-Romance nouv, Romanian nou, Portuguese novo
Common Celtic *novio-, > 
Gaulish novios (new), Old Irish naue, Irish Gaelic nua, Scottish Gaelic nuadh, Manx noa, Breton nevez, Welsh newydd
Hittite newa (new, fresh) 
Avestan nava (new) > 
Ossetic naeuaeg, Pashto nevaj, Baluchi nokh, Tadjik nav
Sanskrit navas (new) > 
 Gypsy nevo, Kashmiri nowu, Lahnda newa, Gujarati newu, Marathi nevin, Punjabi neva, Waziri newai, Bengali notun, noea, Singhalese nava, Nepali naya, Hindi neya, Khaskura naya
Thracian neos (new)
Armenian nor (new)
Tocharian A n'u (new)
Common Germanic *niow-, *nioj- (new) > 
Gothic niujis (new), Old High German niuwi, Old English néowe, níwe (new, recent, not used), Old Swedish niwi, Old Frankish nie; 
German neu, English new, Swedish & Danish & Norwegian ny, Africaans nuwe, Dutch nieuw, Frisian nij, Faroese nyggjur, Icelandic nyr
Common Baltic *nawo- (new) > 
Lithuanian naujas (new), Latvian naujš (in a hurry), Prussian nauns (new), Sudovian naunas, naujas
Common Slavic *novü (new) > 
Ukrainian novij, Bulgarian & Serbo-Croatian & Macedonian & Slovene nov, Czech & Slovak novy, Polish & Sorbian nowy, Belorussian & Russian novy
Notes: A New Year stem. 
This is a rather simple one, it was not subject to mutations and alterations through the history, so has been preserved in various Indo-European groups. The semantic closeness of the meaning "new" to "fresh" and "early" can be proved by substitutes of this very stem by stems with meanings "young" (Latvian jauns) or "fresh" (Scottish Gaelic ur). 
Nevertheless, the second consonant of the stem -w- disappeared in several modern and even ancient tongues, which is natural according to their phonetic systems (e.g. Greek, where Indo-European w steadily disappears or turns into aspiration).