Y-

• A prefix of obscure meaning, originally used with verbs, adverbs, adjectives, nouns, and pronouns. In the Middle English period, it was little employed except with verbs, being chiefly used with past participles, though occasionally with the infinitive Ycleped, or yclept, is perhaps the only word not entirely obsolete which shows this use......
Found on http://thinkexist.com/dictionary/meaning/y-/

Y-

Type: Term Definitions: 1. Abbreviation for yotta-.
Found on http://www.medilexicon.com/medicaldictionary.php?t=100259

y-

Type: Term Definitions: 1. Abbreviation for yocto-.
Found on http://www.medilexicon.com/medicaldictionary.php?t=100261
No exact match found