If you imply something, it’s implicit. If you comply with something, you’re complicit. So why don’t we say you exply something if you make it explicit? I hereby decide and declare that henceforth it shall be so. You can now say “Don’t make me guess what you mean! Just exply it!” Of course, then we’re on our way to saying replies are replicit, which I’m also fine with. And don’t say we already have explain and explicate. Look, implicate isn’t the same as imply and replicate isn’t the same as reply. And complain, complicate, and comply are three different things.
The ply in imply, exply, and reply traces back to Latin plicare, ‘fold’. The prefixes mean ‘in’ (im), ‘out’ (ex), and ‘back’ (re). These also attach to other roots – plain and plete, among others – but I must exply that those are other roots with other meanings. Exply does not mean explain, and replicit does not mean replete. The plain root traces to planus ‘flat’ and the plete root traces to plere ‘fill’.
Not only that, the ply in comply and supply also actually traces to plere ‘fill’, though there has been influence from the other ply words. On the other hand, there’s also complication and supplication, which clearly trace to plicare. And there’s apply, which also traces to plicare, as you can see in applicator (to go with replicator and explicator). So we can do up a little grid:
Asterisks mean they originally trace to a different root. Italics mean they’re not in any dictionary I’ve looked in. They’re unattested but implicit, so I’ve decided to exply them.
Oh… and then there’s duplication and… well, not duplicit but duplicitous. There’s a duply in the Oxford English Dictionary. It means ‘second reply’ or ‘rejoinder’. But no one uses it anymore. So don’t bother with the snappy comebacks.
Thanks to Karen Wise for pointing out the lack of exply in the first place.