Yes, there is a way ( and better ways with highter version than your ).
1) While in Layout Mode create a two rows field
2) Look at the Info pannel and write down the field "height" ( Suppose that that number is 35 pixel )
3) Give to that field an object name ( for example: 1 )
4) Go in the field definition, tab Auto-Enter and check the "calculated value" with calc:
$_height = GetLayoutObjectAttribute ( 1 ; "height" );
$_height > 35 ; "" ;
5) Uncheck the box: "Do not replace existing value for field ( if any )
6) Under tab Validation check Validated by calculation and calc:
$_height ≤ 35 & Let ( $_height = "" ; "" )
7) If you want, write down your custm message.
Now, if you enter MORE than two lines of text, exiting the field you'll have a validation error and the field will be empty.
Note that I do not remember if your version have the $var and the Self function.