"Extensible" vs. "extendible"
Where does the adjective form extensible come from and does it connote anything different than extendible? What's the difference, if any, between the two?
It appears that I probably draw a finer distinction here than others may, but the good thing is that for those that say the two are interchangeable, my usage will seem unremarkable, and for those that care, my usage will seem consistent.
I use extendable in cases where it means the opposite of retractable. In other words, a telescoping wand is extendable, the legs of my camera tripod are extendable.
I use extensible when I mean that the functionality of something may be increased or enhanced by the addition of an extension- an add-on module or component. My web browser is extensible because I can add an Adobe Flash extension which allows me to view flash content. I think it would sound a bit odd to talk about my web-browser being extendable.
There are lots and lots of these. They usually came to us that way straight from Latin, and seldom mean anything different from each other. One may be more rare than another, though.
- comprehendible, comprehensible
- corrodable, corrodible, corrosible
- defendable, defensible
- deridable, derisible
- dividable, divisible
- evadable, evasible
- expandable, expansible
- explodable, explosible
- extendible, extensible
- inevadible, inevasible
- invadable, invasible
- offendable, offensible
- persuadable, persuasible
- protrudable, protrusible
- reprehendable, reprehensible
- rescindable, rescindible
- revisable, revisible
- subdividable, subdivisible
- suspendible, suspensible
- undefendable, undefensible
- undividable, undivisible
The Oxford Dictionary for Writers & Editors says:
extendible, not -able, but in general use extensible not -able