investment vs pellicle

investment and pellicle both are nouns.

Word	Noun	Adjective	Verb	Adverb
investment	Yes	No	No	No
pellicle	Yes	No	No	No

As nouns, pellicle is a hyponym of investment; that is, pellicle is a word with a more specific, narrower meaning than investment:

investment (noun)	pellicle (noun)
the act of investing; laying out money or capital in an enterprise with the expectation of profit	thin protective membrane in some protozoa
the act of putting on robes or vestments
the ceremonial act of clothing someone in the insignia of an office; the formal promotion of a person to an office or rank
outer layer or covering of an organ or part or organism
the commitment of something other than money (time, energy, or effort) to a project with the expectation of some worthwhile result
money that is invested with an expectation of profit