Root - Dairy + Letter Mixed Around

I associate with a group and take only two

I am a sound most people hear in their lives

Root minus dairy plus letter mixed around

A large boulder rests upon my shoulders

Wrapped around a man I lay

Flipped open in the beginning of the birth of a new being

What am I?

Please give explanations for every line. Thanks!

• Welcome to Puzzling SE! I hope you enjoy it here, and that you stay! – NL628 Mar 11 '18 at 6:50

A Ring

I associate with a group and take only two


A mathematical ring is a set(group) equipped with two binary operations.

I am a sound most people hear in their lives


Like a doorbell "ring".

Root minus dairy plus letter mixed around


This one was very hard but I believe it is "Ginger - Egg + G"

A large boulder rests upon my shoulders


A wedding ring has a diamond or other stone on top

Wrapped around a man I lay


Wrapped around a finger? I believe "man" is used as a red herring, because most people relate a wedding ring with the bride, although it can go both ways.

Flipped open in the beginning of the birth of a new being


Marriage ensues (most of the time) with a baby. :D

Remarks: This was a really good first time riddle! I enjoyed solving this especially figuring out the answer to the third line after I finished. I hope you stay!

• Eggs don’t count as milk, usually. – Bass Mar 11 '18 at 7:14
• @Bass Aren't they in the dairy section though? – NL628 Mar 11 '18 at 7:17
• "most people relate a wedding ring with the bride" - obviously it varies by culture, but I know a lot of men who also wear wedding rings. – Rand al'Thor Mar 11 '18 at 12:44
• In the USA, men where wedding rings as often as women. However, wedding rings don’t generally have diamonds on them, only engagement rings (worn by women) do. But that still works because it’s 2 separate clues. – GendoIkari Mar 11 '18 at 14:04
• I believe that last clue refers to opening a jewelry box to reveal the ring in a proposal; this giving birth to the marriage. – GendoIkari Mar 11 '18 at 14:04

I think I'll hazard a guess too, even though I haven't figured the title out yet, since the fit on the final three clues seems more or less airtight (heh).

Are you, by any chance, a

coffin?

I associate with a group and take only two

Koffing is a Pokémon with only two evolutions, Koffing and Weezing.

I am a sound most people hear in their lives

Most people hear coughing in their lives

Root minus dairy plus letter mixed around

..Yeah, haven't figured out this part. Sorry.

A large boulder rests upon my shoulders

A tombstone

Wrapped around a man I lay

That's exactly how you use a coffin.

Flipped open in the beginning of the birth of a new being

This clue seems to be carefully avoiding the words "life" and "human", so..

A vampire's existence begins with an opening coffin.

• Wow I finally got the airtight pun. – NL628 Mar 11 '18 at 22:36