What is a portmanteau and why should you care? The first portmanteau I remember was motel. Originally, it blended the words hotel and motorist, hence a motorist’s hotel. Motel. Now motel is an accepted word found in all dictionaries. My favorite was probably cheeseburger, blending cheese and hamburger. The word smog, blending smoke and fog, has been around as long as I have (long time!). TV cook Rachael Ray created her own portmanteau of stoup (thicker than soup but thinner than stew). Designer dog breed names are portmanteaus: cock-a-poo, labradoodle, puggle, etc.
There are lists of portmanteaus. If you’re interested, do a search. What concerns us as authors is the use of portmanteaus in our writing. Historical fiction writers especially need to know the origins of any portmanteau before using it. The origins might out-date the setting of your story. For instance, in the early 1970s, ranchers began breeding cattle with bison to produce beefalo. Larry McMurtry knew better than to have Gus and Call mention beefalo, motels, or frenemy in his Pulitzer-award-winning novel Lonesome Dove. Call and Gus definitely didn’t have a bromance.
If your character chortles, he or she must live in a time after Lewis Carrol, who created the word from snort and chuckle. Not to be snarky, but did you know snark is a portmanteau of snide remark?
As always, when in doubt look it up. Don’t guesstimate.*
*From guess and estimate