The term 'too skinny' can be described by two crossword solutions: 'LANK' (4 letters) and 'GAUNT' (5 letters). 'LANK' is an adjective meaning thin, slender, or lean. It is derived from the Middle English word 'LANK, ' which means 'long and thin.' 'GAUNT' is an adjective meaning thin and haggard, often due to illness or starvation. It is derived from the Old French word 'gant, ' which means 'thin and bony.' Both words describe someone who is too skinny.