1. （绘画中圣人、天使头上的）光环，光轮
A halo is a circle of light that is shown in pictures round the head of a holy figure such as a saint or angel.

2. 晕;晕状物
A halo is a circle of light round a person or thing, or something that looks like a circle of light.

1. an indication of radiant light drawn around the head of a saint

Synonym: auraaureolenimbusglorygloriole

2. a circle of light around the sun or moon

3. a toroidal shape

e.g. a ring of ships in the harbor
a halo of smoke

Synonym: ringannulusdoughnutanchor ring