ligilo

Decode it. -il- is the tool suffix: the thing you do the verb with. Ŝlosilo is a key, from ŝlosi to lock. Tranĉilo is a knife, from tranĉi to cut. Kombilo is a comb, manĝilo an eating implement, flugilo a wing. So ligi plus -il- is the thing you tie with, and every one of those words is free to anybody who knows the verb.

And then the internet happened. When the web arrived, Esperanto did not need to borrow link: ligilo already meant a thing that connects, and speakers simply pointed it at hyperlinks. It now covers both senses without strain - the string round a parcel and the blue text on a page - and in practice the second is the commoner one. Klaki ligilon is to click a link, rompita ligilo a broken link, ligilo al takes al for what it points at.

This is the whole case for a productive affix system, made in public. Languages that borrow their computing vocabulary end up with words their own speakers cannot decompose; Esperanto met the web with a word it had already built for parcels, and every speaker could parse it on sight. The neighbouring vocabulary went the same way: reto is a net and therefore the network, retejo is the net-place and therefore a website, retpoŝto is net-post and therefore email.

Not to be confused with ligo. Ligo is the connection or bond in the abstract - and also a league, as in an association of countries. Ligilo is the physical or clickable thing that makes the connection.