廢寢忘餐

see 廢寢忘食|废寝忘食[fei4 qin3 wang4 shi2]

to abolish / to abandon / to abrogate / to discard / to depose / to oust / crippled / abandoned / waste

to lie down

to forget / to overlook / to neglect

to forget one's meals

meal / to eat / classifier for meals