לחצן החירום ליד המנגנון.

Roughly: lakh-TSAN ha-khei-RUM le-YAD ha-man-ga-NON.

A few pronunciation notes:

• ח is a throaty sound, like ch in Scottish loch or German Bach.
• צ sounds like ts.
• Hebrew stress is usually on the last syllable here: לחצן, חירום, מנגנון.

So word by word:

• לחצן = lakh-TSAN
• החירום = ha-khei-RUM
• ליד = le-YAD
• המנגנון = ha-man-ga-NON

It is not written, because Hebrew often leaves out is / are in the present tense.

So:

• לחצן החירום ליד המנגנון literally looks like the emergency button next to the mechanism
• but it naturally means The emergency button is next to the mechanism

This is called a nominal sentence. In past or future tense, Hebrew does use a verb:

• לחצן החירום היה ליד המנגנון = The emergency button was next to the mechanism
• לחצן החירום יהיה ליד המנגנון = The emergency button will be next to the mechanism

Because לחצן החירום is a construct phrase (in Hebrew: סמיכות).

Here, Hebrew is literally saying something like:

• button of the emergency

In this structure:

• the first noun usually does not take ה־
• the second noun shows definiteness
• if the second noun is definite, the whole phrase is definite

So:

• לחצן חירום = an emergency button / emergency button
• לחצן החירום = the emergency button

This is why הלחצן החירום is not the normal form here.

No. חירום is a noun, meaning emergency.

English often uses a noun almost like an adjective, as in emergency button. Hebrew does this too, but very often through a construct phrase:

• לחצן חירום = emergency button
• literally: button of emergency

That is different from a real adjective. A real adjective has to agree in gender, number, and definiteness:

• לחצן אדום = a red button
• הלחצן האדום = the red button

But חירום does not behave like an adjective here; it stays a noun.

ליד means next to, beside, or by.

In this sentence:

• ליד המנגנון = next to the mechanism

It is a preposition, so it comes before the noun it relates to.

A useful thing to notice:

• the ה־ belongs to מנגנון
• so המנגנון = the mechanism
• together: ליד המנגנון = next to the mechanism

With pronouns, ליד can also change form:

• לידי = next to me
• לידו = next to him
• לידה = next to her

Yes, both can mean button, but they are not exactly the same.

• לחצן is often a more technical word for a push-button or control button
• כפתור is more general and can mean:
  • a shirt button
  • a keyboard button
  • a device button
  • an on-screen button

So לחצן חירום sounds especially natural for a physical emergency push-button on a machine or system.

Yes. Without more context, Hebrew can sometimes be ambiguous here.

The same words could be understood as:

• a full sentence: The emergency button is next to the mechanism
• or a noun phrase: the emergency button next to the mechanism

Usually context, punctuation, or intonation makes the meaning clear. With a period and ordinary reading, it is very natural to understand it as a full sentence.

מנגנון usually means mechanism, device mechanism, or sometimes system/operating mechanism, depending on context.

It is a masculine noun.

So:

• המנגנון = the mechanism

In technical contexts, it can refer to:

• a mechanical system
• an internal operating part
• sometimes even an organizational or abstract mechanism

Here it most likely means a physical mechanism or device part near the emergency button.