Noun and な adjective
あんぜん
ここまで来れば、安全です。
If I come here, I’m safe.
ゆっくりでかまいませんので、安全うんてんでおねがいします。
I don't mind if we're a little slow, so just please drive safely.
安全第一が私のモットーです。
My motto is safety first.
When you are all relaxed you are finally in safety.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.