As I have gained years and lost callowness, I have acquired an increasing canitude.
A canitude is not a can-do attitude, although I have gotten better at knowing what I can do and at saying I can do things when (and only when) I can do them. Likewise it is not the more certain form of mayitude, and even less of may-junitude (more like decembritude, or at least octobritude). It is not that I sing (as in Arma virumque cano, ‘Of arms and the man I sing’); I have done that since I was a dirty blond. And it is not doggedness (from Latin canis) – that’s a trait I’ve retained from my youth: if I have a problem to solve, I grip it like a bull terrier (and sometimes like a terrible worrier).
Rather, canitude is this:
Grey hair. (Or, for the Americans, gray hair.)
How is canitude greyness? Is it because I’m an old dog? No, it is not: I’m an old cat, and not that old, and anyway I’m always interested in learning new tricks. Nor is it that my hair is singed, or sung of. It’s not even that it’s the colour of an aluminum can (nice and shiny thanks to shampoo). It’s that Latin for ‘grey’ as in hair is canus (or cana or canum, depending on the object) – which can also mean ‘white’ or ‘hoary’ or, when referring to water, ‘frothy’ (see picture above).
This word isn’t used much these days, but there is a related word also descended from canus that rears its head from time to time: canities. This is a medical term and is taken direct from Latin, wherein it means what it means in English: ‘whiteness or greyness of the hair’ (Latin also uses it metonymically to mean ‘old age’). So your canitude is your degree of canities. But because canities entered English in the early 1800s, its pronunciation is influenced by the usual English pronunciation of Latin at the time, so it is, officially and regrettably, “ca-nish-ee-eez.” Which sounds more like sneezing.
But I don’t endorse use of canities; it presents a state of capillary pulchritude – the apogee of hair colour, something I have spent decades eagerly growing into – as a medical condition. Which, sure, like literally every other physical state, it is, but I don’t wish to see it treated as in the same class as pruritus or edema or, in the world of less reversible conditions, presbyopia and kyphosis. No, I will take canitude. As in yes-I-canitude. And if you don’t like my attitude, you can…
Sesquiotica 
The word candidate comes from the same root because a prominent politician had to have his toga very white. (Or maybe candidates had white hair!!)
It’s similar, but not the same root: candidus means shining white, from a verb meaning ‘to shine’. The adjective cānus is a separate word with a different origin.