hakilo

A genuine seam, and one you can trust. Haki is to chop, at rank 1,879. -Il- is the suffix for the tool that does the thing. Put them together and hakilo is "the chopping tool", which is an axe, and you did not need to be told. This is not a coincidence or a helpful mnemonic laid over a borrowed word: it is how the word was made, and if the language had never needed an axe until yesterday the word would still come out hakilo.

The -il- family is one of the best returns on effort in the language. Learn the suffix once and a shelf of vocabulary opens without a dictionary:

• hakilo - a chopping tool, an axe
• tondilo - a shearing tool, scissors
• kudrilo - a sewing tool, a needle
• ŝlosilo - a locking tool, a key
• razilo - a shaving tool, a razor
• skribilo - a writing tool, a pen or pencil, whichever is to hand

English pays for each of those separately, out of four different source languages, and a learner of English has to memorise all six. Esperanto charges you for the verbs and gives you the tools free. The word-building article sets out the whole affix inventory; -il- is the one to learn first because it pays back fastest.

Note what -il- does not mean. It is the instrument, not the person and not the place. The person who chops is a hakisto, the place where chopping happens is a hakejo, and a small axe is a hakileto. Keep -il-, -ist- and -ej- apart from the beginning and you will never write hakisto when you meant the axe. And be careful with martelo, a hammer, which is a plain borrowed root with no seam in it at all: not every tool in Esperanto is built, and there is no verb marteli waiting behind it in the way haki waits behind hakilo. (There is a verb marteli, in fact, but it was derived from the noun and not the other way round, which is the opposite direction of travel.)