Meanings

unrequited love

one-sided trade

snowflake (cluster of ice crystals)

piece (scrap, bit, strip) of paper

flying on one engine

bone fragment

single-swing(ing) door

one lung

unrequited love

one-way ticket

fragment

bare shoulder

writing but receiving no response

slanting, one-sided (shed) roof

one-way fare

speck of cloud

lipped bowl

to lend a hand

single-breasted (jacket, etc.)

petal