One choice is the word peculiar.
5 is odd in digits and five has 4 alphabets which is even
The odd one out is 'Cardinal', as the rest are pieces used in Chess.
Balloon
It was an odd word like pride
The odd one out is 'Cardinal', as the rest are pieces used in chess.
fine
There is more of a negative connotation with that. A better word would perhaps be unique or unusual.
That person has an odd personality. That building looks odd. What an odd hairstyle!
The odd word out is 'happiness', it's not a compound word.
Assuming by meda-leon you mean medallion, the odd one out is applicable, since it's the only adjective and all the other words are nouns. In this answer, I'm assuming Belgian to be a noun, though it could also be used as an adjective. Another possible answer is that Belgian is the odd one out, since it's the only capitalized word. Another possible answer is that meda-leon is the odd one out, since it's the only hyphenated word. Another possible answer is that applicable is the odd one out, since it's the only word beginning with a vowel.
Synonyms for the word odd include strange, peculiar, queer, bizarre.