Visual: This word chelp is a short word with two arms stuck up and one foot stuck down. It has a bump sticking out at either side and a crossed circle (e) in the middle. It has an interesting trend towards – or away from – symmetry. Of course, the first thing you’re likely to see when you look at it is help.
In the mouth: It seems to stay at the front of the mouth: the voiceless affricate on the tip of the tongue, the mid-front vowel, the tongue-tip liquid, and then the stop on the lips to finish it. But rewind to that liquid: if you’re like most native English speakers, your tongue is actually shaped like a banana, the tip up but the middle down and the back curved back up. Oh, and yes, by the way, that ch is pronounced the usual way. This is not “kelp” or “c-help.”
Etymology: Probably a blend of chirp and yelp, but the word is not common or important enough to provoke much research, it seems, and it’s what Oxford calls “dialect” (as if all varieties of a language, even the most esteemed, weren’t dialects – which they are).
Collocations: This word is a verb, but there are citations with your chelp and thy chelp. One thing nearly all the citations have in common: the act of chelping is attributed to another person, most often (among the small sample Oxford gives) the person being addressed. Wordsworth: “Hold your chelp!” D.H. Lawrence: “I’ll stand no more of your chelp.” Keith Waterhouse: “Don’t go chelping back at her like you chelp at me.”
Overtones: It’s not a high-toned word; it seems to be something you put in the mouth of a country character – perhaps one of the help. It has echoes of chill and kelp and chip and maybe jilt, and (reasonably enough) chirp and yelp, and faint hints of such as Chelthenham and jalopy and djellaba. And of course there’s help.
Semantics: Of birds, it means ‘chirp or squeak’. Of people, it means ‘chatter or speak out of turn’; the Collins Dictionary helpfully adds, “esp of women or children.” In other words someone some crotchety guy doesn’t want to listen to while he’s trying to talk at them. But in more modern times it would be a term you could use with anyone to whom you might speak rudely and impatiently. Perhaps such as crotchety guys who are talking at you.
Serve with: You’re most likely to use this in fiction, to put it in the mouth of some rural English sort, and probably not a well-mannered one. But you could always use it in some poetry or some evocative expository text – as long as you put it in a reasonable context. It has a decent onomatopoeia; actually, it sounds like a bird making a doglike sound or a dog making a birdlike sound. The thing to watch out for is just that it doesn’t get inadvertently corrected to help.