1
a [noun] has a [part] that [verb]s
switchblade 为可数名词，表示单数时需加冠词。
A switchblade has a blade that springs open.
弹簧小折刀有一个会弹开的刀片。
弹簧刀；弹簧小折刀
switchblades — plural of switchblade
先理解核心含义，再看它在真实句子里的用法。
弹簧刀；弹簧小折刀
switchblade
A switchblade has a blade that springs open.
弹簧小折刀有一个会弹开的刀片。
按下按钮时刀片在弹簧压力下自动打开的折叠刀。
A folding knife with a blade which opens automatically (under spring pressure) when a button is pressed.
一种按按钮即可弹出刀刃的折叠刀
a pocketknife with a blade that springs open at the press of a button
He pulled a switchblade from his jacket and pressed the button to open it.
他从夹克里掏出一把弹簧刀，按下按钮把它打开。
The shop sells vintage switchblades in a display case near the counter.
这家商店在柜台附近的展示柜里出售复古弹簧刀。
She found an old switchblade under the floorboards while cleaning the room.
她打扫房间时在地板下发现了一把旧弹簧刀。
switchblade 为可数名词，表示单数时需加冠词。
A switchblade has a blade that springs open.
弹簧小折刀有一个会弹开的刀片。
描述触发机制时，常用 when 引导时间状语从句。
The blade of a switchblade springs open when you press the button.
按下按钮时，弹簧小折刀的刀片就会弹开。
Not this
He carried switchblade in his pocket.
Use this
He carried a switchblade in his pocket.
switchblade 是可数名词单数，不能裸用；泛指一把弹簧刀时前面需要加不定冠词 a。
Not this
The police found two switchblade in the car.
Use this
The police found two switchblades in the car.
two 后接可数名词复数，switchblade 的复数形式是 switchblades，不能省略 -s。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
弹开弹簧刀
He flicked open his switchblade and started cleaning his nails.
他弹开弹簧刀，开始清理指甲。
携带弹簧刀
It is illegal to carry a switchblade in many places.
在许多地方，携带弹簧刀是违法的。
隐藏的弹簧刀
Police searched the car and found a concealed switchblade under the seat.
警察搜查了汽车，在座位下发现了一把隐藏的弹簧刀。
弹簧刀法规
Switchblade laws differ around the world.
世界各地的弹簧刀法规不尽相同。
然后他用弹簧刀打了我。
In Johnny Cash's 'A Boy Named Sue', the father strikes his son with a switchblade during their fight.
在约翰尼·卡什的《一个叫苏的男孩》中，父亲在打斗中用弹簧刀打他的儿子。
你想打架吗？我有一把弹簧刀。
The Jets brandish a switchblade and sing this line in 'West Side Story'.
杰茨帮挥舞着弹簧刀唱出这句《西区故事》中的台词。
Use switchblades naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
联想：按一下开关(switch)，刀刃(blade)就“啪”地弹出——弹簧小折刀。
语域：neutral 常见场景：日常谈话、新闻报道、影视/小说 该词指按下按钮即弹出刀刃的小折刀，属于普通名词，语气中性；日常谈话、新闻和影视/小说中都可见到，并不特别正式，也不属于俚语，通常按字面意思使用即可。
也作 switchblade knife，指按按钮即弹出刀刃的小折刀。
Dictionary facts from ECDICT, WIKTIONARY.