The seemingly simple German words “Freund” (m.) or “Freundin” (f.) are quite problematic in actual usage for German learners, because a slight mispronunciation or incorrectly used adjective ending can lead to dramatic confusion regarding gender, amount, and degree of romance in the relationship on the part of the listener.

Particularly “Ich war mit meinen Freunden” (“I was with my friends.”) and “Ich war mit meiner Freundin” (“I was with my girlfriend”) are quite difficult to distinguish when still unsure about how to use the cases. An equivalent word to “buddy”, “mate” (Br. Engl.) or “pal” in German would be convenient. Unfortunately, the word “Kumpel” (a word originally meaning “coal miner”) is mostly used for males, with the female “Kumpelin” is not commonly used. Compare over 8 million Google results for the former to just under 200,000 for the latter. In the Berlin dialect, the word “Atze” (m.) can also be used, but again, refers to males.

Examples:
“Das ist mein Freund.” – “That’s my boyfriend.”
“Das ist ein Freund von mir.” – “That’s my (male) friend.”
“Das ist ein Kumpel von mir.” / “Das ist mein Kumpel.” – “That’s my buddy/mate/pal/bro.”
“Ich gehe zu meinen Freunden.” – “I am going to my friends’ (place).”
“Ich gehe zu meiner Freundin.” – “I am going to my girlfriends’ (place).”
“Ich gehe zu meinem Kumpel.” – “I am going to my buddy’s (place).”

The plural for “Kumpel” is also “Kumpel” or, more colloquially, “Kumpels”.