langweilig
boring
Offering no interest or variety and therefore causing boredom.
Der Film war so langweilig, dass ich fast eingeschlafen bin.
The film was so boring that I almost fell asleep.

boring
Loading your saved state.
boring
Offering no interest or variety and therefore causing boredom.
Der Film war so langweilig, dass ich fast eingeschlafen bin.
The film was so boring that I almost fell asleep.

The word 'langweilig' (boring) is a compound of 'lang' (long) and 'Weile' (while). So it literally describes something that gives you a 'lange Weile' (long while).
Die Wartezeit war langweilig und zog sich ewig hin.
The waiting time was boring and seemed to drag on forever.
Careful: 'Mir ist langweilig' means that you yourself feel bored. 'Ich bin langweilig' means that you are a boring person to others.
Mir ist langweilig, lass uns etwas unternehmen!
I'm bored; let's do something!
'Langweilig' (boring) often describes activities, media, or people. Typical combinations are 'ein langweiliger Film' (a boring film), 'eine langweilige Party' (a boring party), 'ein langweiliger Job' (a boring job), or 'ein langweiliger Mensch' (a boring person).
Ich habe den Job gekündigt, weil er furchtbar langweilig war.
I quit the job because it was terribly boring.
funny
'lustig' and 'langweilig' are clear opposites. You use 'lustig' when something is fun, puts people in a good mood, or makes them laugh. You use 'langweilig' when something is not very interesting and you do not feel well entertained by it. Both words are often used to evaluate films, conversations, classes, parties, or free-time activities. If something is 'lustig', you usually want to keep taking part. If something is 'langweilig', it lacks variety or excitement.

Der Vortrag war leider langweilig, weil der Redner nur Zahlen vorgelesen hat.
Unfortunately, the talk was boring because the speaker just read out numbers.
Das Spiel mit den Kindern war richtig lustig.
The game with the children was really fun.