border, boarder

Border or border means the edge or part of a surface forming an outer boundary--
He wants the sign painted blue, with a red border.
I'm looking for some fabric with a floral border.

Border also means the dividing line between two countries or states--
You'll have to stop at the border, where they'll ask if you have anything to declare.
We'll have to show our passports at the border.

Boarder or boarder ( rhymes with border ) means a lodger or paying guest--
He was a boarder in an old house, and had his dinner there every night.
The old woman wanted to take in a boarder, to help make ends meet.

Boarder might also mean a person who gets on a ship, particularly an enemy ship in time of war--
The doughty sailor knocked  first one boarder overboard, and then another.

Now that you know that, you can say--
"The boarder helped his landlord put up a wallpaper border in the dining room."

Note--"bored her", said of a female ( her ), means wearied or tired by dullness or repetition ( bored )--
She tried to pay attention, but the lecture bored her.
"Board her" would mean to get on a ship--
When he saw the strange ship, the captain determined to board her, and learn her identity.