Standardized extract
A botanical extract guaranteed to contain a minimum percentage of a specific "marker" compound believed to drive the plant's effects (e.g. withanolides in ashwagandha, curcuminoids in turmeric). An unstandardized extract or raw powder carries no such guarantee -- it may contain a similar compound at a much lower, unknown concentration.
Example
Only 3.2% of on-market ashwagandha products are a standardized extract of >=5% withanolides, the type of material used in the largest clinical trials; 49.6% are plain root powder with no guaranteed active content at all.