From Japanese-English FreeDict Dictionary ver. 0.1:
[ichi1] [news2] [nf33] 一 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, １, 壱 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, 弌 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, (word containing out-dated kanji) 壹 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, [ichi1] [news2] [nf33] いち /ˈitɕi/
1. (numeric)
(prefix)
ワン・1 (１ can also be read ワン. 壱, 弌 and 壹 are used in legal documents)
one
2. (nouns which may take the genitive case particle `no')
(suffix)
best
3. (nouns which may take the genitive case particle `no')
first, foremost
4. (noun (common) (futsuumeishi))
beginning, start
5. bottom string (on a shamisen, etc.)
From Japanese-English FreeDict Dictionary ver. 0.1:
[ichi1] [news1] [nf01] 一つ /tsˈɯᵝ/, １つ /tsˈɯᵝ/, (irregular okurigana usage) 一 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, [ichi1] [news1] [nf01] ひとつ /çitˈo̞tsɯᵝ/
1. (numeric)
one
2. (noun (common) (futsuumeishi))
(often used in itemized lists)
for one thing
3. (after a noun)
only
4. (with a verb in negative form)
(not) even
5. (adverbial noun (fukushitekimeishi))
just (e.g. "just try it")
From Japanese-English FreeDict Dictionary ver. 0.1:
一 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, イー /ˈiː/
(numeric)
yīone
From Japanese-English FreeDict Dictionary ver. 0.1:
一 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, 逸 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, いっち /ˈittɕi/
(adverb (fukushi))
Note: archaismmost
From Japanese-English FreeDict Dictionary ver. 0.1:
[spec1] 一 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, [spec1] ひと /çˈito̞/, ひ /çˈi/, ひい /çˈiː/
1. (prefix)
一・いち・1 (esp. ひと)
one
2. (numeric)
(when counting aloud, usu. ひ or ひい)
one