The IUPAC name for CH2OH is hydroxymethyl. Before finding the IUPAC Name of CH2OH, we need to be aware of 3 important rules：

(1) Alkyl (Prefix)

(2) Functional groups (Suffix)

(3) Structural formula (Alkyl + Functional groups)

If the given formula (CH2OH) satisfies the above 3 rules, we can easily find it's name.

(1) Alkyl (Prefix): 1C - Meth; 2C - Eth; 3C - Prop; 4C - But; 5C - Pent. Here, only 1 Carbon is there. So, it's prefix will be Meth -.

(2) Functional groups ( Suffix): Alcohol (OH): -ol; Aldehyde (CHO): -al; Carboxylic (COOH): - oic acid. Here, -OH group is there. So, it's Suffix will be -ol.

(3) Structural formula ( Alkyl + Functional groups): For all kinds of functional groups, the formula will remain same. CnH2n+1 - OH - Alcohol; CnH2n+1 - CHO - Aldehyde; CnH2n+1 - COOH - Acid. Here, n represents the No. of Carbon.

Here, 1 carbon is there. So, for 1 carbon = 3 Hydrogen atoms should be there ( Exclude the functional group). From the question CH2OH, for 1 carbon, we are having only 2 hydrogen rather than 3 hydrogen. So, it doesn't satisfy the 3rd rule.

First of all, It's not a molecule or a compound. It's a Substituent (i.e Side chain) of some larger compound like Serine (Amino acid). Hence, it's Name is, -CH2OH - Hydroxymethyl.