It's so weird seeing you guys use Estonian words!
I'm attempting to give you some literal translations for these. And I've also hyperlinked the names as well for easier exploring.
Lawn-nan would be the literal translation. This one is hard to bring over. Mother of Meadows is way more poetic and sounds right.
An utterly benevolent nature spirit. Wife of Metsaisa (Father of the Woods). They have eternally young daughters that play and laugh all night... and love to bathe in the summer moon light. They're also benevolent, unless you go and peek their bathing, in which case they'll make you deaf or blind. It's possible to take one for a wife if you manage to catch one, but a man can't find happiness with them. She will always return to her sisters sooner or later. Seeing them can also be sort of a curse, as they're so beautiful and create agonizing longing.
Hiid is one the words for a Giant. Our national epic
Kalevipoeg (Son-of-Kalev) has a giant for a main character. And both of our great isles have a famous giant that originates from their soil. In fact, our second largest isle is called Hiiumaa -- An Isle of Giants.
Alternatively, it's also our word for a
Jötunn.
I'd translate these as the
Old Man of the Bog and
The Wild One.
Oddly, "vana" means just "old" with no gender implied, but when used in such a compound word, I don't think it would be conceivable for any Estonian to imagine anything other than a male. As the word "vana" can be appended to basically any noun and still make sense
Old Man of the X is pretty common in our stories. Vetevana (Old Man of the Waters) usually grants wishes, but unlike a genie or a gold fish, tends to have a temper and a sense of poetic justice.
Our word for a Mermaid. The translation doesn't make much sense for the "mer" part, as our native mythology doesn't associate them with sea, but with bogs and lakes instead. However in modern use, it can also stand for the literal mermaids from the sea (although we have the word "merineitsi" for the more benevolent mermaids as well).
Näkk can also be male. The male ones usually turn into horses, and when a maid or a child goes to ride on them, they drag them to the water.
The Spring Healer. As in a water spring. I'm drawing a blank on this one, so, I can't comment on it.
Under-the-Rock. That one's completely new for me as well. It could be that they they mean a rock spirit to whom ancient Estonians brought sacrifices to. The large sacrificial rocks often had naturally formed bowls on them as a spot to place the offering.
