"Kegel" has three common translations. If you are not into bowling or mathematics, jump to translation 3!

1. (ten)pin [noun] [de kegel, de kegels]

A "kegel" is also used for the (nine)pin in the game of skittles ("kegelspel", with associated verb "kegelen") but in the Netherlands this is not a common game, contrary to bowling.

Example:
– "Te gek, in één worp alle kegels omver!!" 
("Super/cool! All pins down in one throw!" Note that "omver" implies falling over and it is usually combined with the verb that causes the movement such as "gooien" ("to throw"), "stoten" ("to bump/knock") etc.)

Related words:
– Bowlen: to bowl [verb] [bowlde, gebowld].
– Bowlingbaan: bowling alley [noun] [de baan, de banen].
– Bowlingbal: bowling ball [noun] [de bal, de ballen].

2. cone [noun] [de kegel, de kegels]

Here "kegel" is the three-dimensional geometric shape "cone". The word is also used for anything that is shaped like a cone.

Examples:
– "De inhoud van een kegel bereken je als volgt: …" 
("One calculates the volume of a cone as follows:…")

– "Mijn favoriete ruimtelijke figuur is de kegel." 
("My favourite three-dimensional shape is the cone.")

– "Verkoopt u ook wierook in de vorm van een kegeltje?"
("Do you also sell incense in the shape of a small cone?")

Related words:
– Cilinder: cylinder [noun] [de cilinder, de cilinders].
– Bol: sphere [noun] [de bol, de bollen].

3. badly smelling alcohol breath [noun] [de kegel, de kegels]

Now this is one you should know. Whenever one is not talking about bowling or a cone, it must be about badly smelling alcohol breath! Mind that the word is obviously used informally.

Examples:
– "Ik ben naar de tandarts geweest vanochtend en die gast had een enorme kegel, ongelofelijk!" 
("I have been to the dentist this morning and that bloke/guy was reeking of alcohol, unbelievable!")

– "Ga nou maar slapen, je hebt een enorme kegel!" 
("Just go to bed will you, your breath smells of alcohol." Lit. "you have an enormous..")

Related words:
– Alcohol: alcohol [noun] [de alcohol, no plural].
– Dronken: drunk [adjective].