A reasoned forecast of the likely cost of work based on the information and assumptions available at the time.
Why it matters
An estimate is not automatically a fixed-price commitment. Its purpose and level of certainty should be stated.
Example in practice
An early estimate uses elemental rates while the design is still too incomplete for a fixed-price quote.
Use the term carefully
State the scope, amount, adjustment method or contract meaning whenever this term could change who carries cost or risk.