1
appear fleetingly
fleetingly 常与表示出现、闪过之类的短暂动词连用，强调持续时间极短。
The actor appeared fleetingly in the opening scene.
那位演员在开场戏中短暂地出现。
短暂地；飞快地
先理解核心含义，再看它在真实句子里的用法。
短暂地；飞快地
in a fleeting manner; swiftly
The actor appeared fleetingly in the opening scene.
那位演员在开场戏中短暂地出现。
短暂地；转瞬即逝地
in a fleeting manner; transiently
I saw her fleetingly at the station before the train left.
火车开走前，我在车站匆匆瞥见了她。
The thought crossed my mind fleetingly and then disappeared.
这个念头在我脑海中一闪而过，然后就消失了。
He smiled fleetingly when he heard the joke, then returned to his work.
他听到笑话时微微一笑，然后继续工作。
fleetingly 常与表示出现、闪过之类的短暂动词连用，强调持续时间极短。
The actor appeared fleetingly in the opening scene.
那位演员在开场戏中短暂地出现。
用于修饰微笑等表情时，表示转瞬即逝，常带一种不易察觉的意味。
She smiled fleetingly before looking away.
她短暂地笑了笑，然后把目光移开。
该结构强调只是快速、短暂地看到，没有机会细看或交流。
I saw him fleetingly at the conference.
我在会议上匆匆地见过他一面。
Not this
The moment passed fleeting.
Use this
The moment passed fleetingly.
修饰动词 pass 应用副词 fleetingly；fleeting 是形容词，不能作状语。英语中修饰动词用 -ly 副词，对应中文的“地”字结构。
Not this
She gave me a fleetingly glance.
Use this
She gave me a fleeting glance.
glance 是名词，需要形容词 fleeting 来修饰；fleetingly 是副词，不能作定语。中文的“飞快的一瞥”中“飞快的”对应英语形容词。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
短暂出现
The singer appeared fleetingly on stage before the lights went out.
歌手在灯光熄灭前短暂出现在舞台上。
微微一笑
She smiled fleetingly when she heard the good news.
听到这个好消息时，她微微一笑。
匆匆瞥见
We glimpsed the old castle fleetingly through the fog.
我们透过雾气匆匆瞥见了那座古堡。
简短提及
He mentioned the incident fleetingly in his speech.
他在演讲中简短地提到了这件事。
转瞬即逝
The summer passed fleetingly, and soon the children were back at school.
夏天转瞬即逝，孩子们很快就返校了。
短暂可见
The moon was fleetingly visible through the breaking clouds.
月亮在云隙间短暂可见。
Use fleetingly naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
想想“舰队”(fleet)飞速驶过只留下瞬间，fleetingly 就是“飞快地、短暂地”。
语域：formal 常见场景：文学描写、正式书面语 fleetingly 通常用于书面或文学语境，表示“短暂地、飞快地”；在日常口语中比较少见。
These words all end in -ingly (except sweetly, which is a lookalike), so they help with the spelling of fleetingly. The -ingly ending is pronounced /ɪŋli/ in each of them, but none rhymes exactly with fleetingly /ˈfliːtɪŋli/ because the stressed syllable or the consonant after it differs. Sweetly /ˈswiːtli/ looks and sounds similar at the start but lacks the /ŋ/ before -ly.
Dictionary facts from ECDICT, WIKTIONARY.