help, typically of a practical nature

he saw the pilot slumped in his cockpit and went to his aid

she walked with the aid of a Zimmer frame

a grant of subsidy or tax to a king or queen

help or support (someone or something) in the achievement of something

women were aided in childbirth by midwives

research was conducted to aid in making decisions

a disease in which there is a severe loss of the body's cellular immunity, greatly lowering the resistance to infection and malignancy