Are these straightforward alternatives, or is there a difference in meaning? I was just making a post to another forum and couldn't decide which to use.

I'd say that they are straightforward alternatives with the following proviso.

In British slang "unfeasible" has taken on the additional meaning of "improbable" especially in its adverbial form "unfeasibly". We hear things like "Russel Brand has no talent but an unfeasibly bad hair cut" or "Jordan has no talent but unfeasibly large breasts."

I've never heard "infeasible" used in this way.

On this side of the pond I've not heard "infeasible" at all.

I've heard both but I'd say that unfeasible seems much more common.

quote:

I've heard both but I'd say that unfeasible seems much more common.

Ditto.

I'm with Geoff on this one...

Hello

I've joined the forum just so I can tell you about my friend who used to describe things as "unfeasonable" (inadvertantly, I hasten to add.)

I loved this portmanteau term and my other friends and I immediately adopted it and bandied it about with merry abandon. It brought us much joy.

Good first post, Alphabet Soup! If something can be unreasonable, I suppose it can also be unfeasonable! Or if he's a French fashionista, something might be unfaisonable.

Welcome Alphabet! Now we hope you stay awhile.

quote:

Originally posted by Geoff:
Good first post, Alphabet Soup! If something can be unreasonable, I suppose it can also be unfeasonable! Or if he's a French fashionista, something might be unfaisonable.

Hahaha! He was no fashionista though, he was pretty mouldy really (unfraisonable, even )

We use the word feasible in Chemistry a lot.

I always thought the opposite of feasible was simply not feasible, or non-feasible.

According to the OED, infeasible is now (1989) rarer in use.

I agree with Graham. I hear not feasible, rather than in or un. We often talk about feasibility studies in research.

Of course the coinage proposed by Alphabetsoup is the humpty-dumptyish portmanteau

unfeasonable = unfeasible + unreasonable

which I love. Of course I'd love a humpty-dumpty word!

Welcome to the board btw.

quote:

Originally posted by BobHale:
Of course I'd love a humpty-dumpty word!

That's not how I'd use the term "Humpty-Dumpty word". Lewis Carroll certainly used the character of Humpty-Dumpty to introduce the idea of portmanteau words, but to me the term "Humpty-Dumpty word" refers to the character's well-known remark:

quote:

'When I use a word,' Humpty Dumpty said in rather a scornful tone, 'it means just what I choose it to mean -- neither more nor less.'

An example might be "democratic", used in the names of some of the least democratic countries in the world.

quote:

Originally posted by BobHale:
Of course the coinage proposed by Alphabetsoup is the humpty-dumptyish portmanteau

unfeasonable = unfeasible + unreasonable

which I love. Of course I'd love a humpty-dumpty word!

Welcome to the board btw.

Thanks for the welcome I'm glad you like 'unfeasonable', I think it's a corker.

In the interests of saying something on-topic, I'm familiar with the word 'unfeasible', it's a pretty normal word to my ears, but I hadn't heard 'infeasible' before reading this thread.

quote:

I think it's a corker

Interesting word, corker. My grandmother used to use it. In looking it up, it can mean either "something or someone that is astonishing or excellent" or "something that closes a discussion or settles a question." Quite a difference!

In anticipation of criticism, I know it's not perfect. However, I like to use Google to see how popular words are. Infeasible, on my computer, gets 1,950,000 citations, while unfeasible gets 1,450,000 citations.

I wonder, does this^ constitute an 'infeasibilty study'?

A cursory glance at the interwebs suggests that it is we curmudgeonly Brits who object to 'infeasible' whereas it is an acceptable term to you forward thinking American types.