THIS is the adorable moment a five-month-old baby said "hello" to his mum for the first time.

Single mum Lyndsey Keenan, 28, was filming her babbling baby Roman when she caught him clearly saying "hello".

Mother-of-two Lyndsey’s "jaw dropped" when she caught Roman on camera saying his first ever word, months before anyone expected.

Lyndsey, a stay-at-home mum, who lives in Eastbourne, can be heard saying "hello" back as she chuckles at the unexpected moment last month.

The Argus: Mother-of-two Lyndsey Keenan with baby RomanMother-of-two Lyndsey Keenan with baby Roman

Tiny Roman, who has an older brother called Lex, 10, was born six weeks premature in July.

READ MORE: Meet Sussex's Christmas Day baby 

Lyndsey questioned if her little boy "might be a little bit behind" - but it seems he is actually well ahead.

She said: “Roman had made little noises before that, but never a full word.

“We hadn’t been expecting him to talk yet anyway, especially as he was born six weeks early so I thought he might take longer.

“He was just babbling away like normal when he came out with that. It was so strange, because he says it so clearly.

“I couldn’t believe I managed to catch it on video too. I immediately rang my friend to tell her what had happened.

“He’s an intelligent little boy at just five months - when he says ‘hello’, it feels like he really means it!”