Sentence:  However , the conversion from mass to size is unreliable , since <WSD>many</WSD> photographic meteors give evidence of a fluffy , loosely bound meteorite structure with densities as low as * * f . 
Meaning of the word marked with <WSD> tags:  a quantifier that can be used with count nouns and is often preceded by `as' or `too' or `so' or `that'; amounting to a large but indefinite number